Main PC Hardware Tuning & Acceleration
PC Hardware Tuning & AccelerationVictor Rudometov, Evgeny Rudometov
From choosing overclocking tools and setting the optimal mode to allowing the fulfillment of the potential of a PC's components, this reference discusses solutions to the problem of computers not performing well enough to accommodate requested tasks. Examined are the particular features of using processors, memory, video adapters, and hard drives both in moderate and extreme modes while trying to obtain a substantial rise in performance for both old computers and computers that contain more modern components. The results of testing computers with various configurations that have overclocked components are also demonstrated. A list of helpful web sites pertaining to acceleration is provided, as well as a guide to choosing components. Also covered are several advanced overclocking topics such as ways of making the CPU and motherboard compatible and the problems with overclocking IDE devices.
[image: Previous Section] < Day Day Up > [image: Next Section] Back Cover[bookmark: BACKCOVER] Sooner or later, every computer user runs into the problem of the computer not being able to perform well enough to solve the tasks it needs to. Even after you have optimized the computer’s hardware and software from all sides, there still comes a point where your only choice seems to be to either modernize your system or buy a new computer altogether. However, there is still one more reserve that you can call on—using acceleration for the components of your computer, which will allow them to realize some hidden potential capabilities while increasing the performance of the system. We must note here that overclocking modes can be used both as a means of finding out the potential of the technology and architecture that you use, and as a tool for predicting their further development. And for a few enthusiasts, this mode can be an absorbing pastime and a means of proving oneself. Using overclocking modes has won adherents not only among users, but also among large computer companies. The leading hardware and software producers provide for support of overclocking modes. Choosing these tools and setting the optimal mode to allow you to fulfill the potential of the components are not easy tasks. Various solutions to these problems are what we will examine in this book. In it, we will list particular Features of using processors, memory, video adapters, hard drives, etc., both in moderate and extreme modes, while trying to obtain a substantial rise in performance for both old computers and computers that contain much more modern components. About the Authors Victor Rudometov is a computer scientist and a technical writer. Evgeny Rudometov has a Ph.D. in control systems and is an IBM-certified specialist in designing control systems, software, and hardware. They are the authors of PC Overclocking, Optimization, & Tuning, 1st Ed and 2Ed. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] PC Hardware Tuning & Acceleration VICTOR RUDOMETOV EVGENY RUDOMETOV [image: ] Copyright © [bookmark: 6][bookmark: IDX-iv]2004 by A-LIST, LLC All rights reserved. No part of this publication may be reproduced in any way, stored in a retrieval system of any type, or transmitted by any means or media, electronic or mechanical, including, but not limited to, photocopying, recording, or scanning, without prior permission in writing from the publisher. A-LIST, LLC 295 East Swedesford Rd. PMB #285 Wayne, PA 19087 702-977-5377 (FAX)
http://www.alistpublishing.com This book is printed on acid-free paper. All brand names and product names mentioned in this book are trademarks or service marks of their respective companies. Any omission or misuse (of any kind) of service marks or trademarks should not be regarded as intent to infringe on the property of others. The publisher recognizes and respects all marks used by companies, manufacturers, and developers as a means to distinguish their products. ISBN 1-931769-23-0 Printed in the United States of America 04 05 7 6 5 4 3 2 1 A-LIST, LLC, titles are available for site license or bulk purchase by institutions, user groups, corporations, etc. Book Editor: Julie Laing[bookmark: 7][bookmark: IDX-v] About the Authors Victor Rudometov is a computer scientist and a technical writer. Evgeny Rudometov is an IBM-certified specialist in designing control systems, software, and hardware. They are the authors of PC Overclocking, Optimization, & Tuning. [bookmark: 8][bookmark: IDX-vi][bookmark: 9][bookmark: IDX-vii][bookmark: 10][bookmark: IDX-viii] [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch01] Chapter 1: From the Industrial Era to the Information Age [bookmark: 14][bookmark: IDX-1] Recent advances in technology have rapidly pushed humanity from an industrial age to a period that can be characterized mainly as informational. Computers gradually have become cheaper and more readily available. Their power and functional capabilities increase at a rapid pace. All these factors allow them to be used in practically every field of human activity. However, efficient usage of modern computers requires both advanced infrastructure and a certain level of user skill. These elements are essential to making the most of the high potential of computer hardware. The advent of calculating devices during the industrial age was a logical stage of evolution: Science, technology, and industry require a high processing speed of intensive information flows. At first, the problem was alleviated by the creation of data-processing centers. These were based on sophisticated information-processing centers, which were very powerful (for that time) and, consequently, rather expensive. These centers were serviced, maintained, and supported by numerous highly qualified professionals. Recall the dinosaur machines of the 1960s and 1970s, known as mainframes: A typical mainframe was capable of processing 100,000 to 2 million simple 32-bit register-to-register operations per second. The amount of Random Access Memory (RAM) installed on such machines varied from several hundred kilobytes to several megabytes. Although such parameters are laughable today, they were impressive at that time. [bookmark: 15][bookmark: IDX-2] A data-processing revolution took place about two decades ago, with the arrival of personal computers oriented toward individuals. The user-friendly interface (both hardware and software) of PCs significantly lowered the level of user knowledge and skill from that required by previous-generation computers. [bookmark: 16][bookmark: ch01fig01][bookmark: IMG_2][image: Click To expand] Figure 1.1: First IBM PC, developed in 1981 [bookmark: 17][bookmark: ch01fig02][bookmark: IMG_3][image: Click To expand] Figure 1.2: Contemporary PC equipped with a wireless keyboard [bookmark: 18][bookmark: IDX-3] Personal computers are created with relatively cheap components. The central element of the PC is the processor. The first microprocessor was designed and manufactured by Intel engineers, and this historic event began an era of cheap microprocessors. This first processor was named Intel 4004. Parameters of this key component were relatively modest: a clock frequency of 108 kHz, 0.06 MIPS (millions of instructions per second, or 60,000 operations per second), 2,300 transistors, 10 micrometer (μm) technology, a 4-bit bus, and 640-byte addressable memory. Still, it was the first chip used for arithmetical operations, and the computing power of this processor exceeded that of the ENIAC, the world's first electronic computer. The Intel 4004 microprocessor was officially released on Nov. 15, 1971. [bookmark: 19][bookmark: ch01fig03][bookmark: IMG_4][image: Click To expand] Figure 1.3: First processor released by Intel [bookmark: 20][bookmark: ch01fig04][bookmark: IMG_5][image: Click To expand] Figure 1.4: Intel Celeron 2 GHz processor Since that time, processors have become much more powerful and sophisticated. The number of transistors has increased thousands of times, the clock frequency has grown significantly, and the potential capabilities of the processors have been extended dramatically. [bookmark: 21][bookmark: IDX-4][bookmark: 22][bookmark: ch01table01] Table 1.1: Number of Transistors in Intel Processors Processor Year of release Number of transistors 4004 1971 2,250 8008 1972 2,500 8080 1974 5,000 8086 1978 29,000 286 1982 120,000 386 1985 275,000 486DX 1989 1,180,000 Pentium 1993 3,100,000 Pentium II 1997 7,500,000 Pentium III 1999 24,000,000 Pentium 4 (Willamette) 2000 42,000,000 Pentium 4 (Northwood) 2001 55,000,000 Processors with different architecture and power have been the basis for several generations of computers. This allowed for the creation of a variety of computers; it also provided a foundation for transition from centralized to decentralized information processing. Within a short period, billions of computers have been manufactured, ensuring the possibility of decentralized data processing. This factor made possible the wide use of an enormous number of computers in practically all spheres of human activity. As a result, the working style of millions of people has changed dramatically. Even more importantly, the development priorities of contemporary society have changed. Information has become an object of labor, as well as an important and valuable product. In the industrial societies of economically advanced countries, about 90% of total profits are related to information processing, accumulation, and sales. The efficiency of these activities strongly depends on the functional capabilities of computers, which, in turn, are dependent on the advancement of technology, information infrastructure, and the computer literacy of the population. These factors have top priority in the evolution of contemporary society and have attracted close attention from its members. Processors comprising a billion transistors are expected to be released in 2007. As Intel Chief Executive Craig Barrett mentioned in a report at an Intel Developer Forum (IDF) session, within 15 years, advances in semiconductor technology are [bookmark: 23][bookmark: IDX-5]expected to enable processor architects to implement products with parameters that include the following: CPU clock frequency of 30 GHz 1 trillion instructions per second 2 billion transistors Transistor size of 10 nanometers (0.01 micrometers) Note IDF is the largest technological conference for leading developers in which representatives of the mass media participate. IDF sessions are held several times each year in countries around the world. At these sessions, leading manufacturers discuss new and emerging technologies and products in the electronic industry. Traditionally, spring and autumn sessions take place in California. Other sessions often are held outside the United States. Technological advances in the field of computing allow continual performance improvement and extend the functional capabilities of contemporary computers. However, the transition from centralized to decentralized data processing, accompanied by steady growth in the number of individuals involved in the process, has given birth to numerous problems — many unknown until recently. Some problems arose with the personalization of computers. This is reflected in the name of the most popular class of computers — personal computer, or PC. Availability, relatively low prices, and individual usage of these devices necessitate personal maintenance of computers. At the same time, the choice and the initial configuration of a particular computer are determined at the time of purchase. Final tuning of hardware and software is accomplished either by third-party specialists or by computer users themselves. Such an approach ensures an optimal set of system software and application programs. This, in turn, allows efficient solutions to tasks and customization of the interface according to the individual preferences of the computer owner, or end user. However, the personalization of computers compels end users to have some technical background and to constantly improve their computer skills. Without this, it is impossible to optimally tune both hardware and software. Overall performance, stability, and reliability of the system mainly depend on the quality of hardware customization and software fine-tuning. It is expedient to repeat the procedure of fine-tuning on different computer subsystems when new types of problems need to be solved or after the computer hardware and software have been upgraded. [bookmark: 24][bookmark: IDX-6] Using the appropriate customization and running some utilities can compensate for negative changes to certain parameters in the course of long-term operation. These changes are usually related to the natural degradation of electronic components over time. To improve performance, it is useful to periodically upgrade device drivers and their Basic Input/Output System (BIOS). Operations such as scanning and defragmenting hard drives must be performed regularly. Ignoring these operations results in performance degradation, and, in the worst case, data loss. It is necessary to track all news related to software patches and to upgrades of operating systems and third-party software. The computer, which currently comprises millions of transistors distributed over hundreds of chips, has become a sophisticated system. It probably is the most sophisticated device designed by human beings. Like any complicated device, the computer has many hidden capabilities. Knowing and rationally using these hidden features of computer components allows them to be implemented to their fullest potential. This allows for the improvement of performance and the extension of the functional capabilities of hardware and software tools. Thus, humanity has entered an age of informational civilization, which evolves according to its own laws and rules and has its own dead-ends, dangers, advantages, and interesting new capabilities. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch02] Chapter 2: Philosophy of Hardware Overclocking [bookmark: 26]Overview [bookmark: 27][bookmark: IDX-7] The complexity of system programs and application software is steadily increasing. Each individual can choose, purchase, and fine-tune a computer. Some time later, the PC user inevitably encounters performance problems when attempting to complete new tasks. After resources for improving computer performance by optimization have been exhausted, the user must take a more radical approach, such as purchasing a new computer, upgrading the existing one, or even using overclocked modes. Computer performance and its functionality strongly depend on the parameters of the components in computer system and on their coordinated operation. It is not sufficient to choose a computer and determine its hardware components and software configuration. A computer must be fine-tuned and customized if you want to achieve maximum performance from its components and maximum efficiency from its functional capabilities. Furthermore, like any complicated device, a contemporary computer needs maintenance and service, and its software and hardware components must be used correctly. If you ignore these requirements, an expensive contemporary computer will operate less efficiently than earlier and significantly cheaper models that have been optimally tuned. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch02] [bookmark: 28][bookmark: ch02lev1sec1]Solving the Problem of Limited Resources [bookmark: 29][bookmark: IDX-8] Even the newest computer that has been carefully selected and is regularly serviced cannot keep pace with constantly growing requirements. Sooner or later, you will face problems caused by inadequate performance for solving tasks. When there are no more resources for increasing the performance by optimizing computer hardware and software, radical measures must be employed. Some people solve the problem of insufficient performance by purchasing a new computer; others try to upgrade an existing one. Both approaches involve financial expense, which can be significant. In addition, insufficient performance can occur on relatively new and workable computers, even those purchased less than a year ago! Most PC users feel frustrated by this situation, and they search for ways to complete tasks while retaining the existing computer. Some people invent new methods and algorithms that allow them to solve problems with limited resources. Other people simply reduce the range of tasks they solve using a computer. They often abandon contemporary operating systems with convenient but resource-consuming interfaces. They prefer more economic but less advanced operating systems of previous generations. A computer with such limited resources often runs simple, obsolete programs that efficiently complete a limited range of unsophisticated tasks. [bookmark: 30][bookmark: ch02fig01][bookmark: IMG_6][image: Click To expand] Figure 2.1: Traditional solution to the problem of limited resources A community of a different type of computer users balances cost with the rapid rate of technological advancement. People from this community often replace existing hardware, and in most cases, they are prepared to purchase a new computer. [bookmark: 31][bookmark: IDX-9]Still, they have a clear understanding of the disadvantages of this approach, and many try to find an alternative. Such people realize the necessity of financial investment. They purchase the required devices and/or the newest computer hardware, then get rid of the existing equipment. Later, they either call experts or, if they have the required experience and qualifications, proceed through the steps that upgrade their computers. In the course of such multistep upgrades, they gradually replace obsolete components with high-performance ones that provide broader functional capabilities. However, some serious problems often prevent people from upgrading such computers. These problems are mainly related to further technological advances and to improvements of the architecture and quality of the components. The fast progress of silicon manufacturing technologies often fails to provide backward compatibility or compatibility with standards, interfaces, or architectural solutions. These factors regularly become an obstacle to upgrading computers. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch02] [bookmark: 32][bookmark: ch02lev1sec2]Evolution of Technologies and Components Computing technologies are evolving, and new hardware and software appear constantly. Therefore, the lifetime of computer hardware components shortens constantly. As new components with higher performance and better quality appear on the market, it becomes economically unjustifiable to work with obsolete prototypes. This happens despite advances in manufacturing technology, reliability improvements, and the mean time between failures (MTBF). [bookmark: 33][bookmark: ch02table01] Table 2.1: Evolution of Intel Manufacturing Processes Process name P854 P856 P858 Px60 P1262 P1264 Implementation (year) 1995 1997 1999 2001 2003 2005 [[bookmark: N111]*] Lithography (nanometers) 350 250 180 130 90 65 Gate length (nanometers) 350 200 130 <70 <50 <35 [[bookmark: ftn.N111]*]anticipated Currently, the average maximum lifetime of processors, video adapters, and hard disks is five years. However, most people try to replace these components while they still are usable and operating satisfactorily. Typical computer users replace components after two or three years. However, the high reliability of computer components makes it possible to use them for more than ten years. [bookmark: 34][bookmark: IDX-10] [bookmark: 35][bookmark: ch02fig02][bookmark: IMG_7][image: Click To expand] Figure 2.2: Forecast for the evolution of Intel's semiconductor technology These estimates also apply to central processing units (CPUs). Despite their complexity, these components are capable of working ten years or more. Still, significant changes, often referred to as new architecture, are introduced into the core of CPUs every three or four years. Standards for processor slots, via which CPUs are installed on motherboards, change even more frequently. Newer and more advanced processor models manufactured within the same line of products are usually released every few months. These newer models often are incompatible with the platforms designed for their predecessors, even if the processor-slot type is preserved. For example, Intel Pentium processors with MMX technology were designed, like earlier models of Intel Pentium, for the Socket 7 slot. However, in contrast to their predecessors, PMMX processors required motherboards that provided two levels of a processor's core voltage. This means that newer processors based on the P5 architecture required platform replacement. A similar situation took place with the arrival of processors created using 130-nanometer technology. Like their predecessors — Intel Pentium III processors based on 180-nanometer technology — they had P6 architecture. However, despite retaining the same type of socket — Socket 370, generally manufactured in those days — the newer processors needed a change of core voltage as well as the release of new chipsets. Once again, this meant that new motherboards were required. Similar situations even took place for high-tech products. The evolution of CPU architecture and the form factors for Intel Pentium 4 processors also initiated corrections and changes to the PC platforms that supported these processors. Changes in power supply became traditional; they took place not only with changes [bookmark: 36][bookmark: IDX-11]to core architecture, but also with the migration from 180-nanometer to 130-nanometer technology. Form factors of the released models also changed. The Socket 423 standard, introduced for the earliest models of these processors, lasted only one year. After that, it was replaced by the incompatible Socket 478, which, as usual, required newly designed and manufactured motherboards and power supply units (i.e., a complete replacement of the PC platform). [bookmark: 37][bookmark: ch02table02] Table 2.2: Evolution of Intel Processor Architecture for Desktop PCs Processor Slots Year of release 8086 - 1978 286 - 1982 386 - 1985 486DX Socket 1/Socket 2/Socket 3/Socket 6 1989 Pentium/Pentium with MMX technology Socket 4/Socket 5/Socket 7 1993 Pentium II/Pentium III Slot 1/Socket 370 1997 Pentium 4 (Willamette/Northwood/Prescott) Socket 473/Socket 478/Socket T (Socket 775) 2000 Advances in computing technologies have changed other components, such as video adapters. Within a short time interval, the video subsystem of the PC has cycled through the following interfaces: Industry Standard Architecture (ISA), Video Local Bus (VLB), Peripheral Component Interconnect (PCI), and Accelerated Graphics Port (AGP). These interfaces have several types of specifications, which set standards for a range of specialized video adapters. For example, the AGP video adapters that dominate today's market have evolved over several generations: AGP 1X, AGP 2X, AGP 4X, and AGP 8X. They differ not only in performance, but also in the requirements of their electric, logical, and design interfaces, which makes video-adapter compatibility impossible. A new, advanced, and promising interface, PCI Express (at development time, it was known as 3GIO), also requires new designs for video adapters and motherboards. As a result of this interface evolution, platforms change every two or three years, keeping pace with the release of new lines of video adapters that support more advanced interfaces. [bookmark: 38][bookmark: IDX-12][bookmark: 39][bookmark: ch02table03] Table 2.3: Evolution of Video Adapters Video adapter Throughput (MB/sec) Year of release ISA 8 1984 VLB 100–133 1992 PCI 133 1993 AGP 266 1997 AGP 2X 533 1998 AGP 4X 1,066 1999 AGP 8X 2,100 2002 PCI Express 2,100+ 2004 [[bookmark: N446]*] [[bookmark: ftn.N446]*]anticipated The situation with RAM is no less dramatic. RAM also is subject to constant changes of types, interfaces, and form factors. During the relatively short time that has elapsed since the arrival of the first PCs, several mutually incompatible types of RAM have appeared. [bookmark: 40][bookmark: ch02table04] Table 2.4: Evolution of RAM RAM type Year of release FPM DRAM 1992 EDO DRAM 1994 SDRAM (SDR SDRAM) 1997 DRDRAM 1999 DDR SDRAM 2001 DDR II SDRAM 2004 [[bookmark: N531]*] [[bookmark: ftn.N531]*]anticipated Each RAM type had several versions with different frequency and timing parameters. For example, Single Data Rate (SDR) Synchronous Dynamic Random Access Memory (SDRAM), usually referred to as just SDRAM, has modules corresponding to PC66, PC100, and PC133 specifications. (The digits in the specification names designate their maximum operating clock frequencies: 66 MHz, 100 MHz, and 133 MHz.) Double Data Rate (DDR) SDRAM contains modules designed to operate at frequencies of 100 MHz, 133 MHz, 166 MHz, and 200 MHz. DDR SDRAM ensures a data rate twice that of SDR SDRAM, even at the same [bookmark: 41][bookmark: IDX-13]frequencies. DDR SDRAM modules are intended to operate at 2.5 V, SDR SDRAM at 3.3 V, and Extended Data Output (EDO) SDRAM at 3.3 V or 5 V. Compatibility is complicated by different form factors for modules released at different stages of microprocessor evolution. Examples of common form factors of the RAM module include Single In-line Pin Package (SIPP), Single In-line Memory Module (SIMM), Dual In-line Memory Module (DIMM), and the RIMM memory module. (RIMM often is referred to incorrectly, with "R" standing for "Rambus." However, the term RIMM is not an acronym; it has been trademarked.) Each form factor has several variants with different sizes and different numbers of pins. [bookmark: 42][bookmark: ch02fig03][bookmark: IMG_8][image: Click To expand] Figure 2.3: Forecast for the evolution of RAM It should not be necessary to prove that these differences result in the incompatibility of memory modules. Other components, such as hard disks, also evolve at a rapid rate. During the last few years, hard-disk capacity usually doubled every 9 to 12 months. The MTBF declared by manufacturers often exceeds 500,000 hours. In contrast to processors, video adapters, and RAM, new hard-disk models retain compatibility with earlier models for a long time. For example, ATA100 (100 MB/sec) disks can be connected to ATA66 (66 MB/sec) and even to ATA33 (33 MB/sec) controllers. However, with such connections, you cannot get the maximum speed potential. Furthermore, it is impossible to achieve the full compatibility of Advanced Technology Attachment (ATA) devices with controllers implementing Serial ATA150 (150 MB/sec) and Serial ATA300 (300 MB/sec) interfaces. The same relates to the compatibility between Serial ATA150 devices and parallel interface ATA100/66/33 controllers. [bookmark: 43][bookmark: IDX-14][bookmark: 44][bookmark: ch02table05] Table 2.5: Evolution of the ATA Interface Bus Throughput (MB/sec) Year of release ATA16 16.7 1996 ATA33 33.3 1997 ATA66 66.7 1999 ATA100 100 2000 ATA133 133 2001 Serial ATA150 150 2002 Serial ATA300 300 2004 [[bookmark: ch02table05fnt01]*] Serial ATA600 600 2007[*] [bookmark: 45][[bookmark: ftn.ch02table05fnt01]*]anticipated [bookmark: 46][bookmark: ch02fig04][bookmark: IMG_9][image: Click To expand] Figure 2.4: Forecast for the evolution of the ATA interface The data provided in this chapter prove that the rapid progress of semiconductor technologies and of the architecture of computer components doesn't allow standards, interfaces, and form factors to be retained for long periods of time. [bookmark: 47][bookmark: IDX-15][bookmark: 48][bookmark: ch02table06] Table 2.6: Lifetime of Architectures, Standards, and Components Components Period (years) Processors 3–4 Video adapters 2–3 RAM 2–3 Hard disks 1–2 Under such conditions, after several years of operation, it becomes impossible to upgrade a computer system by simply replacing obsolete components. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch02] [bookmark: 49][bookmark: ch02lev1sec3]Last Resort for Performance Improvement Besides purchasing a new computer or optimizing hardware and software, there is another way to improve computer performance. This approach prolongs the lifetime of a usable machine that rapidly becomes obsolete. Furthermore, it often gives a "second life" to a computer that hardly can be classified as "modern." This approach uses special methods of enhancing performance. The underlying idea of these methods is to exploit some computer components in forced modes to get the most out of their hidden reserves. As a rule, this significantly improves the speed of each component, increasing overall system performance. One of the most common methods of achieving a forced mode of operation is to increase the clock frequency beyond the level recommended by the manufacturer. That's why these methods are generally known as overclocking. The possibility of overclocking is the consequence of manufacturing principles. It is impossible to ensure that a factory will produce identical processors. A similar situation exists for video adapters and RAM chips. Therefore, to guarantee that the manufactured components satisfy the declared requirements, manufacturers have to provide some performance reserve. This is especially true with the implementation of new technologies and architectures, whose initial performance barely differs from that of earlier products of the line. This hidden performance reserve usually can be implemented via forced modes such as overclocking. Note that forced modes sometimes are achieved at the expense of component stability and, consequently, overall system reliability. In addition, forced modes usually decrease the MTBF parameter. In many cases, this is acceptable. Taking into account the duration of expedient usage of computer components, a possible decrease of reliability and the MTBF (for example, from 10 or 20 years to 5 years) [bookmark: 50][bookmark: IDX-16]often is justified. The system would remain usable until it became obsolete. In addition, as previously shown, upgrades become problematic after a certain amount of time. However, if overclocking procedures are used expertly, system crashes and hang-ups will be rare, and they seldom will produce fatal results. The use of forced modes for server components is not recommended. Furthermore, the use of such modes should be prohibited in computer systems that manage potentially dangerous or critically important tasks at nuclear power stations, chemical industries, rocket launching facilities, hospitals, etc. In these areas, computer failures potentially are more dangerous than in homes or offices. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch02] [bookmark: 51][bookmark: ch02lev1sec4]Concepts, Principles, and Stages of Overclocking Forced modes extend the lifetime of obsolete computers that can't be upgraded because of the reasons given in this chapter. Recently, however, this method of performance enhancement became popular even among the users of brand-new PCs. The cases in which such users ask someone to overclock a computer before its purchase are not rare. Experienced PC users prefer to overclock newly purchased computers at home, carefully choosing optimal modes, and then carefully testing all subsystems at all overclocking stages. Thus, improvement of overall system performance is one of the main goals of overclocking. Overclocking is popular not only because of the natural desire, characteristic of most advanced PC users, to improve the computer architecture. The main reason behind its adoption lies in the field of economics. The overclocking procedure achieves relatively high performance for relatively little financial cost. For example, performance gain for processors might increase 20% to 30%. With extreme overclocking modes (which are more risky), performance may improve 50% or more. Proceeding the similar way, the performance of RAM, a video adapter, and even a hard disk can be improved significantly. An overclocked computer automatically moves into a higher category. Lower-level components often compete successfully with more powerful and expensive products. The most important fact here is that this goal can be achieved without additional financial investment. Processor overclocking alone can save you several hundred dollars. You can compensate for decreased reliability by observing several recommendations and taking some simple steps. By following these recommendations, you can work successfully with an overclocked system for a long time. [bookmark: 52][bookmark: IDX-17] Note that the popularity of overclocking has a negative effect on the economical interests of manufacturers. Most aren't willing to lose even a small part of their profits. Apart from this, some individuals use overclocking capabilities to gain illegal profits. For example, such individuals may fake a trademark; supply fraudulent components, including processors and memory chips; then sell them as more advanced and more expensive components. Some small companies go further: They manufacture ready-to-use systems based on overclocked components and sell them without informing their customers about the overclocking. To counteract potential fraud and protect their commercial interests, most leading manufacturers introduce features into their modules mainly aimed at preventing fraudulent distribution and limiting performance improvement, making it difficult to use overclocked modes of operation. Despite these efforts by brand-name manufacturers, overclocking popularity gradually has increased. The arrival of appropriate motherboards and chipsets, as well as the release of specialized software, serves as a catalyst to this process. The contemporary market consists of a variety of specialized tools that maintain optimal temperature modes for computer components. This simplifies the process of setting overclocked modes and of testing the system in various modes of operation. However, improving system performance by using overclocking mustn't be considered only from the economical point of view. The newest units and components often operate in overclocked modes, even though the initial performance of these components is high. Current silicon-manufacturing technologies allow performance to be increased much higher than the level declared by manufacturers. In addition, most advanced PC users have a natural desire to predict the evolution of computer components. Hence, they have a goal beyond financial savings: Use forced modes to investigate the architecture of different elements and forecast the development of current technologies. The investigation of forced modes and the development of recommendations interest not only addicted individuals (also known as overclocking fans), but also many serious companies all over the world. Such research work even may be sponsored by leading manufacturers. (The cooperation between KryoTech and AMD, mentioned in some publications, is an illustrative example. As a result of this research work, AMD processors in an extremely overclocked mode reached the barrier of 1 GHz long before the release of processors for which this clock frequency was routine.) The interest in the overclocking problems manifested by some manufacturers can be easily explained. This research work helps them improve the architecture and enhance the performance of their products. Apart from this, it allows them to accumulate valuable statistical information on malfunctions and failures, which [bookmark: 53][bookmark: IDX-18]helps them develop efficient hardware and software tools that improve reliability. Finally, the ability of computer hardware components to retain stability in over-clocked modes serves as excellent promotional material for products. Some companies use the experience and technologies accumulated by overclockers in their manufacturing process and attempted to supply high-performance hardware. For example, Compaq was supplying high-end server platforms based on technologies developed by KryoTech for the extreme cooling of AMD Athlon and similar processors operating at clock frequencies that exceeded recommended values 1.5 to 2 times. The results of cooperation and research conducted by famous and respectable companies have stimulated the growth of an army of enthusiasts. Most of them view extreme overclocking as a kind of sport. As the number of overclocking fans grows, the number of Web sites dedicated to this topic increases. These sites consider various aspects of overclocking problems that might arise, and provide useful recommendations. The materials provided in this book attempt to explain overclocking topics systematically and produce both general and specific recommendations for tuning and overclocking the main elements of a computer. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch03] Chapter 3: Moderate and Extreme Overclocking Modes [bookmark: 55]Overview [bookmark: 56][bookmark: IDX-19] Modern computer components have significant hidden performance reserves provided by contemporary manufacturing technologies. These hidden reserves can be used to improve performance considerably. This can be achieved via forced modes — either moderate overclocking with partial implementation of reserves, or an extreme variant that gets the most out of potential reserves of computer-hardware components. The problem of using computer components (particularly processors) in forced modes has been avidly discussed in recent years. Many publications and Web sites (some references will be provided in the appropriate sections of this book) have been dedicated to this topic. Overclocking procedures are aimed at enhancing the functional capabilities of computers, the most important goal being performance gain. Note that numerous methods allow you to achieve this goal. These methods include hardware tuning for a specific configuration, as well as fine-tuning of the operating system and application software. Optimization of the chosen operating system holds a special place among these operations. Regular maintenance procedures are also important. All of these operations are aimed at achieving the maximum possible performance of the computer. Further reserves for performance improvement are related to implementation of the overclocking potential, which often remains hidden from end users. [bookmark: 57][bookmark: IDX-20]The measures that implement this hidden potential include special operating modes of computer components and the usage of special software tools such as accelerators and drivers. Besides this, newer versions of BIOS codes can be useful. Versions developed for powerful high-performance devices also may be suitable. Overclocked modes with the optimal choice of external and internal clock frequencies are the most important means implementing hidden reserves. This ensures the possibility of achieving maximum performance of computer hardware. Motherboard manufacturers, trying to attract potential users, not only support overclocking capabilities, but also promote and popularize features that support the possibility of using such modes. Some manufacturers even supply software products with their motherboards that simplify the implementation of overclocked modes. As a result, the overclocker community has grown. Even official overclocking contests have become a common event. Different people have different views of the overclocking problem. Some users are not excited by this aspect. Others consider themselves the principal opponents of overclocking, based on the well-grounded opinion that performance gain that results from overclocking has a negative effect on the overall stability and reliability of a system's components. The third category of users contains the overclocking fans. Each party has strong arguments and deserves respect; therefore, each user must make his or her own choice. Nevertheless, things aren't that simple as they might seem at first glance. Overclocking isn't a panacea for performance improvement. It cannot help you to turn your Intel Pentium III into an Intel Pentium 4. There are two types of overclocking. These differ in both method and goal. The first type is known as extreme overclocking, or overclocking for its own sake. When choosing this approach, extremely high results can be achieved. However, practical work in such modes might be impossible, because both overclocked systems and their operating conditions are usually exotic. This may remind you of Formula One cars: They race at nearly aerospace speeds and they are unsuitable for driving under normal conditions. Such extreme overclocking is usually incompatible with stable operation of processors; therefore, it is of little or no interest to ordinary PC users. Some people even consider extreme overclocking to be a kind of extreme sport. Extreme overclocking normally requires cryogenic cooling via liquid gases. Such experiments are usually conducted to report specific records. Under current conditions, extreme overclocking can be considered research work, which contributes to contemporary scientific knowledge. Another type of overclocking is achieved without a negative effect on overall system stability. Moderate overclocking is the optimal compromise between high [bookmark: 58][bookmark: IDX-21]performance and excellent reliability. This sort of overclocking interests the vast majority of users. For this reason, it is the main topic of this book. This type of overclocking also can be used for scientific evaluation of the capabilities of semiconductor technologies and the architecture of specific computer-hardware components. Such evaluation can be used to predict future development. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch03] [bookmark: 59][bookmark: ch03lev1sec1]Growth Problems and Hidden Reserves When overclocking is discussed, it usually relates to the processor, and often to the memory modules. Most individuals define overclocking as a forced increase of the clock frequency. As a result of such operations, computer performance improves considerably. If you purchase a system equipped with Intel Pentium 4, operating at a frequency of 1.6 GHz, and with DDR266 memory modules (DDR SDRAM operating at 266 MHz), you could use straightforward manipulations to make it operate as Intel Pentium 4 with a frequency of 2.4 GHz equipped with DDR333 memory modules. Detailed instructions on performing these procedures will be covered later in this book. Here, a general understanding will be given of the CPU clock frequency specified in the product names of various processors (such as Intel). CPU clock frequency, usually expressed in gigahertz, determines the time interval, also known as clock, during which the processor executes a specific number of instructions. If a processor has a clock frequency of 1 GHz, then 1 clock equals 1 nanosecond (nsec). If a processor has a clock frequency of 2 GHz, 1 clock is half the length of that from the previous processor; therefore, it equals 0.5 nsec. Consequently, the processor is capable of executing the same number of instructions twice as fast (if both processors execute the same number of instructions per clock). Based on these facts, the performance of the second processor is twice that of the first processor. In practice, however, this conclusion is not quite right. At this point, the term processor performance should be clarified. From the end user's point of view, processor performance is the time required to execute a specific set of commands that make up the program code. The smaller this time interval, the greater the performance of the processor installed in a specific system. This means that performance can be considered the number of commands executed per clock multiplied by the CPU clock frequency: Performance = (Commands per clock) × (Clock frequency) The number of commands executed per clock depends both on the program being executed and on the processor architecture (i.e., which set of commands can be processed and how this job is done). At the processor level, each command [bookmark: 60][bookmark: IDX-22]is converted into a set of several machine instructions or elementary commands. The efficiency of this transform depends both on the processor architecture and on the code optimization for specific processor architecture. Besides this, depending on the processor architecture, elementary commands can be executed in parallel. These considerations make it clear that it would be incorrect to compare the performance of processors that have different architecture if that comparison is based only on their clock frequencies. Some applications might run more efficiently on AMD processors; other ones may perform better on Intel processors with the same clock frequency. However, within one processor family (i.e., processors that are based on the same architecture but have different clock frequencies), such a comparison would be correct. Thus, to increase the processor performance, it is expedient to raise its clock frequency. To be more precise, the improvement is made to the semiconductor core, the basis of this key computer component. Each processor is intended to operate at the specified clock frequency. If the manufacturer declares that a processor is designed to run at 1,600 MHz, this is an objective reality, rather than simple declaration. Intel Pentium 4 processors of 1,600 MHz and 2 GHz are manufactured using the same technology, under the same conditions, and at the same technological line. However, various circumstances can cause deviations from specified parameters, which result in slightly different characteristics of the final products. To detect such deviations and their consequences, manufacturers perform technological control and testing of their products. Naturally, it is impossible to test each processor separately, especially taking into account the scale of production. The common practice is to perform selective testing of each party of the final product. During this testing, the manufacturer determines the general ability of the processors to run at a specific clock frequency. Then, the entire group of processors is marked according to that frequency. A specific processor purchased by a customer may not have undergone the procedure of selective testing; thus it may be capable of supporting a higher clock frequency than the declared one. Finally, each manufacturer provides some "reliability reserve" that accounts for static dispersion of parameters, because it is impossible to guarantee reproduction of manufacturing processes. As a result, most processors can run at increased clock frequencies (i.e., they can be successfully overclocked). However, as processor manufacturing technologies become more advanced, the static parameter dispersion narrows. This enables manufacturers to supply more powerful processors and gradually decrease their "reliability reserve." As a result, low-end models are more promising to overclockers than high-end ones (Fig. 3.1). [bookmark: 61][bookmark: ch03fig01][bookmark: IMG_10][image: Click To expand] Figure 3.1: Performance reserve for low-end and high-end processor in various overclocking modes [bookmark: 62][bookmark: IDX-23] Fig. 3.1 shows performance reserve for low-end and high-end processors in different overclocking modes. The dark area corresponds to moderate overclocking modes; the light area shows extreme modes, which sometimes can be implemented only under specific conditions. Which effects and physical processes prevent unlimited growth of the internal frequencies of the semiconductor core? Recall that contemporary processors installed in modern PCs comprise millions of elementary units made of transistors manufactured using Complementary Metal-Oxide Semiconductor (CMOS) technology. Furthermore, a semiconductor core, such as Northwood, created using 130-nanometer technology and serving as the basis for Intel Pentium 4 processors, comprises 55 million of transistors. Its successor, the Prescott core, manufactured according to the 90-nanometer technology, comprises more transistors. The size of each sophisticated unit is smaller than the size of a typical flu virus. These millions of transistors are connected to one another in specific ways, are concentrated in an extremely small area, and often operate at frequencies that already exceed 10 GHz. All these elements can produce [bookmark: 63][bookmark: IDX-24]negative effects on one another. This can be illustrated by an example of two adjacent conductors that connect elements of the processor core. [bookmark: 64][bookmark: ch03fig02][bookmark: IMG_11][image: Click To expand] Figure 3.2: Two adjacent conductors that connect elements in the processor core These conductors are characterized by mutual capacitance. This capacitance depends on the distance between them and on the area of the facing sides. The value of this capacitance is calculated according to a well-known formula C = k × S/d, where C is the capacitance, S is the area, d is the distance, and k is permittivity coefficient, whose physical meaning will be considered later. For a direct current, this configuration is a reliable dielectric; at high frequencies, mutual capacitance generates uncontrolled currents because the capacitor formed by the two conductors has a certain conductivity. Although conductors are small, the distance between them also is very small. The high values of the frequencies and the high number of conductors (there are millions of them) means their influence on the frequency properties of the internal core structures is not negligible. This is especially true because each capacitor, besides capacitance, is characterized by resistance and inductance. This means that the equivalent circuit of the configuration formed by two conductors represents a set of capacitors, resistors, and inductors. It has the properties of the integrating circuit with multiple resonance frequencies. Furthermore, there is mutual influence among several conductors. This statement is illustrated by Fig. 3.3, which presents the configuration that would be formed by three conductors. [bookmark: 65][bookmark: ch03fig03][bookmark: IMG_12][image: Click To expand] Figure 3.3: Three neighboring conductors that connect core elements Undisputedly, the frequency properties of such a configuration are considerably more complex than those of the diagram formed by two conductors. Both active (resistors) and reactive (capacitors and inductors) components of the impedance are distributed along the entire length of the conductors. This significantly complicates the behavior of such systems at high frequencies. The situation is worse because conductors do not operate in vacuum. On the contrary, they are surrounded by a medium with specific dielectric properties, which influences [bookmark: 66][bookmark: IDX-25]the values of mutual capacitance. Furthermore, materials used in chip manufacturing have permittivity that exceeds 1; therefore, the values of mutual capacity are higher than those produced by the cases just considered. An approximation that illustrates this situation is in Fig. 3.4. [bookmark: 67][bookmark: ch03fig04][bookmark: IMG_13][image: Click To expand] Figure 3.4: Two conductors, with consideration for dielectric influence Based on this illustration, it is clear why designers try to use materials with smaller values of permittivity (k) to insulate semiconductor chips. [bookmark: 68][bookmark: IDX-26] The frequency characteristics in all these cases depend on a range of factors: the size of conductors, their mutual position, the chemical composition of conductors and of surrounding dielectrics, microscopic defects, etc. Any variation in these parameters changes the frequency characteristics. This explains why the "reliability reserve" is mandatory for sophisticated components operating at high frequencies. Besides conductor topology, it is necessary to consider the influence of transistors, whose structure and physical nature are more complicated than those of individual conductors. Besides controlling currents, transistors themselves are powerful sources of electromagnetic radiation. Transistors also influence adjacent elements and are exposed to similar effects. The p-n-junctions present in their structure can perform detection of undesirable parasitic currents, their amplification, and their transmission. It is hard to imagine the intensity of the electromagnetic field within a processor chip; the elements are packed so densely that they are characterized by alternating fields of high intensity. These fields form a complicated structure that changes depending on the different operating frequencies of internal processor structures, forming maximums and minimums in different areas of the chip. [bookmark: 69][bookmark: ch03fig05][bookmark: IMG_14][image: Click To expand] Figure 3.5: Transistor structure The general pattern is even more complicated, especially because at current transistor sizes, the influence of quantum effects is considerable and gradually increases. These effects, despite advances in transistor architecture, increase uncontrolled currents. Their total flow represents a combination of currents generated by insulation defects, those generated by leaks of a different nature via capacitors, and even the ones caused by the tunnel effect. This part of the uncontrolled current is large, and it tends to grow with an increase in clock frequency. This also requires manufacturers to provide reliability reserve in their products. To compensate for negative effects and ensure stable CPU operation at higher frequencies, manufacturers have to increase core voltage. Compare the core voltages [bookmark: 70][bookmark: IDX-27]for low-end and high-end processors. For high-end models, the core supply voltages are always higher, no matter which architecture and manufacturing technology is used. If you increase the clock frequency above the standard level and need to ensure reliable operation of the processor (as well as of the RAM modules, graphics processor of the video adapter, and video memory), you also need to increase the voltage. For moderate overclocking, this increase must not exceed the maximum values recommended by the manufacturer. These parameters are provided in technical documents known as datasheets. Usually, the limiting values established by processor manufacturers are approximately 10 percent above the standard value. Provided that normal operating conditions are ensured, which primarily relates to the temperature modes, such an increase doesn't result in a significant decrease of the processor's lifetime due to the rapid degradation of semiconductors. Unfortunately, increasing the power-supply voltage and clock frequency also increases the temperature, which can be evaluated by the following formula: P ≈ C × V2 × F Here, P is the heat generated by the CPU, in watts; C is the correction factor that accounts for the mutual capacitance of the processor-core components, depending on its architecture; V is the power-supply voltage; and F is the clock frequency in gigahertz. This formula can be expressed as follows: [image: ] The variables with the index of k designate overclocked parameters; the variables with the index of 0 represent standard values. Table 3.1 presents an evaluation of the expected heat generation for an Intel Pentium 4 processor with a standard operating frequency of 2 GHz in different overclocking modes, with P0 = 52.4 W and V0 = 1.50 V. [bookmark: 71][bookmark: ch03table01] Table 3.1: Evaluation of CPU Heat Generation (Pk) with Different Fk and Vk Values Fk(GHz) 2.1 2.2 2.4 2.6 Vk(V) 1.50 1.50 1.55 1.60 Pk(W) 55.0 57.6 67.1 77.5 [bookmark: 72][bookmark: IDX-28] If a processor's clock frequency is decreased until it is below its standard value, the core voltage also can be decreased appropriately without disrupting overall system stability. According to the previous formula, this decreases the heat emitted by the processor. Such operations are usually performed automatically by combinations of specific hardware and software. Normally, they are intended to reduce power consumption and are typical for mobile computers. However, the same approach is also applicable to desktop computers. Note that in recent years, the generated heat has increased even for standard operating modes. This happened despite PC designers' constant efforts to improve CPU internal structures and decrease the core voltage. Decreasing the core voltage became possible with the reduction of the transistor sizes, and, consequently, a decrease in the sizes of their gates. The gate controls the source-drain current. The thinner the gate, the lower the voltage required to maintain field intensity. A reduction in the channel length is accompanied by a reduction of losses. The newest research aimed at improving transistor topology also helps improve parameters. Thus, technological advances and improvement of processor architecture ensure an increase of CPU clock frequencies (Fig. 3.6). [bookmark: 73][bookmark: ch03fig06][bookmark: IMG_16][image: Click To expand] Figure 3.6: Exponential growth of processor performance (based on IDF data) [bookmark: 74][bookmark: IDX-29] Unfortunately, this performance growth also has a dark side: increased heat emission. The area of the processor chip hardly changes; therefore, this growth in heat emission results from increased energy density. [bookmark: 75][bookmark: ch03fig07][bookmark: IMG_17][image: Click To expand] Figure 3.7: Growth of the energy density inside a processor chip, compared to other densities (based on IDF data) Under conditions of inadequate cooling, the high heat emission overheats the processor's internal structures, which negatively affects its reliability and speeds up the processes of semiconductor decay. Semiconductors are sensitive to heating. The average energy of atom oscillations grows with the temperature. As a result, the number of broken links in the grid of the silicon crystal grows, and new pairs of electrons and holes appear. When the temperature limit is reached, semiconductor properties change. For example, conductivity of semiconductors and dielectrics grows as the temperature rises. As a result, the system begins to malfunction, and failures become persistent. To avoid these negative effects, it is necessary to use adequate cooling. Currently, no high-performance processor can operate without a high-quality cooler equipped with a massive heatsink and a powerful fan. It would be logical to suppose that by taking special steps to ensure CPU cooling, stable operation of chips designed for room temperature can be achieved. Note that such chips are usually overclocked to frequencies that considerably exceed the standard values. In particular, such measures (which are not actively promoted) were used at an Intel Developer Forum (IDF) session during a demonstration of standard processors in extreme overclocking modes. [bookmark: 76][bookmark: IDX-30] Among the facilities that ensure extreme overclocking, a special place is held by the cooling facilities that reduce the CPU temperature below the ambient temperature. Specially designed freezers (or freezing chambers) are used for this purpose. This idea isn't new or revolutionary; most corporations specializing in high-end servers demonstrated temperature overclocking at least at an experimental level. Such manufacturers include Sun Microsystems, IBM, and Compaq. In 1991, Intel and NCR started "temperature overclocking under manufacturing conditions," a project known as Cheetah. The portfolio of patents registered within the range of this project later became the property of the six founders of KryoTech, who at that time were working as researchers for NCR. Later, these developments enabled KryoTech professionals to create a range of facilities that ensure efficient cooling of overclocked CPUs, at the expense of placing them, with motherboards, into freezing chambers. Cryogenic methods of cooling overclocked components also can be considered variants of such solutions. Some details of such experiments that relate to extreme CPU overclocking will be presented later in this chapter. However, before proceeding to extreme overclocking, consider some aspects of traditional moderate overclocking modes. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch03] [bookmark: 77][bookmark: ch03lev1sec2]Moderate Overclocking of Processors (Based on materials and with the permission of Russian magazine ComputerPress.) CPU overclocking is based on the performance growth of the processor's core and integrated L2 cache memory (and, consequently, on overall performance growth), caused by an increase in the operating clock frequency. Both the core and L2 cache operate at the internal CPU clock frequency. [bookmark: 78][bookmark: ch03fig08][bookmark: IMG_18][image: Click To expand] Figure 3.8: Core, cache memory, and buses of an Intel processor [bookmark: 79][bookmark: IDX-31] Besides the CPU clock frequency, other parameters must be considered, such as the Front Side Bus (FSB) frequency and the memory-bus frequency. The FSB frequency is the main operating frequency of the entire computer system. All other frequencies, which define the operations of computer subsystems and the data exchange among them, are synchronized with it. In contemporary computers based on the Intel Pentium 4 processor, the FSB frequency can take values of 100 MHz, 133 MHz, and 200 MHz. It is expected that the FSB frequency will increase with technological advances and improvement of the architecture of semiconductor elements. On this bus, the duration of one clock is determined by rectangular voltage pulses. The arrival time of each new pulse is defined by its front (leading edge). The processor bus, also known as the system bus, connects the processor to the North Bridge of the chipset. This bus is used by the processor for communication with all the other devices. [bookmark: 80][bookmark: ch03fig09][bookmark: IMG_19][image: Click To expand] Figure 3.9: CPU and RAM connection to the North Bridge In computers based on the Intel Pentium 4 processor, data travel on the system bus at the frequencies of 400 MHz, 533 MHz, and 800 MHz. This means that in the Intel Pentium 4 processor, the data-transmission frequency is four times that of the FSB frequency, and the address-transmission frequency is twice that of the FSB frequency. If the FSB frequency is 100 MHz, then the data-transmission frequency is 400 MHz, and the address-transmission frequency is 200 MHz. If the FSB frequency is 133 MHz, then the data-transmission frequency is 533 MHz. At an FSB frequency of 200 MHz, data are transmitted at 800 MHz. This value usually is provided in CPU and motherboard specifications. [bookmark: 81][bookmark: IDX-32] Besides the frequency, the processor bus is characterized by its throughput (i.e., by the maximum amount of data that can travel via this bus per second). The CPU bus has a width of 64 bits, which means that it can transmit 64 bits (8 bytes) per clock. Consequently, if it operates at 400 MHz, its throughput is 3.2 GB/sec (400 MHz × 8 bytes). At 533 MHz, its throughput will equal 4.2 GB/sec. [bookmark: 82][bookmark: ch03fig10][bookmark: IMG_20][image: Click To expand] Figure 3.10: Organization of data transfer via the SDR SDRAM bus [bookmark: 83][bookmark: ch03fig11][bookmark: IMG_21][image: Click To expand] Figure 3.11: Organization of data exchange via the DDR SDRAM bus [bookmark: 84][bookmark: IDX-33] The memory-bus frequency defines the speed of data exchange between the processor and the memory controller (located in the North Bridge). This frequency depends on the memory type and is synchronized with the FSB frequency. For the most common types of DDR memory, data transfer occurs twice per clock, both at the leading and trailing edges of the clock pulse. This means that the effective frequency of a memory operation is twice the clock frequency. The predecessor of DDR memory — SDR SDRAM — transmitted data at a frequency that coincided with the memory-bus frequency. For DDR200, DDR266, DDR333, and DDR400, the effective frequency that defines the data-transmission speed is equal to 200 MHz, 266 MHz, 333 MHz, and 400 MHz, respectively. The clock frequency is 100 MHz, 133 MHz, 166 MHz, and 200 MHz, respectively. The memory-bus frequency is synchronized with the FSB frequency. For example, if the FSB frequency is 133 MHz, the memory frequency relates to the FSB frequency as shown in Table 3.2. [bookmark: 85][bookmark: ch03table02] Table 3.2: Frequency Relationship between DDR Memory and FSB DDR memory frequency (MHz) FSB frequency (MHz) Multiplier Throughput (GB/sec) 200 133 1.5 1.6 266 133 2.0 2.1 333 133 2.5 2.6 400 133 3.0 3.2 Like the system-bus frequency and the memory-bus frequency, the CPU clock frequency is synchronized with the FSB frequency. The coefficient that relates the CPU clock speed and the FSB frequency is known as the multiplier. For example, if the FSB frequency is 133 MHz and the multiplier equals 18x, Intel Pentium 4 processor will operate at a frequency of 2.4 GHz. For an Intel Pentium 4 processor with a clock frequency of 2 GHz, the multiplier will equal 20x, provided that the FSB frequency is 100 MHz. At first, it might seem that the easiest way to increase the internal (core) clock frequency of the processor is to increase the multiplier value. If you have an Intel Pentium 4 processor operating at 1.6 GHz with a standard multiplier of 16x (and an FSB frequency of 100 MHz), you can turn it into an Intel Pentium 4 with a frequency of 2.4 GHz by simply changing the multiplier to 24x. This method is simple and reliable, but, in all contemporary processors, including those of the AMD Athlon family, the possibility of changing the multiplier is disabled. [bookmark: 86][bookmark: IDX-34]In AMD processors, it is still possible to sidestep this limitation using some tricks. (Information on this will be described in the appropriate sections of this book.) It is impossible to overcome this limitation in Intel Pentium 4 and Intel Pentium III. Don't let this upset you. Recall that the CPU clock frequency is synchronized with the FSB frequency. Therefore, if you increase the FSB frequency, the CPU clock frequency will increase automatically. Motherboard manufacturers provide the capability of increasing the FSB frequency. For example, the nominal clock frequency of an Intel Pentium 4 processor is 2.4 GHz at an FSB frequency of 133 MHz (which means the multiplier is set to 18x). By increasing the FSB frequency to 180 MHz, the CPU frequency increases to 3.2 GHz (Table 3.3). [bookmark: 87][bookmark: ch03table03] Table 3.3: Increasing the CPU and Memory Clock Frequencies with the FSB Frequency FSB frequency (MHz) CPU clock frequency (GHz), 18x multiplier System bus frequency (MHz) System bus throughput (GB/sec) DDR266 memory frequency (MHz) Memory throughput (GB/sec) 133 2.4 533 4.2 266 2.1 140 2.5 560 4.4 280 2.2 150 2.7 600 4.8 300 2.4 160 2.8 640 5.1 320 2.5 170 3.0 680 5.4 340 2.7 180 3.2 720 5.7 360 2.8 Overclocking a system by increasing the FSB frequency also increases the memory frequency, because RAM is synchronized with the processor clock frequency. This circumstance is important, although it often is overlooked by PC users. You can never know what will die first: the memory or the processor. Furthermore, the memory usually is the main hindrance to overclocking; it can prevent you from increasing the FSB frequency. If the processor is capable of operating at an FSB frequency of 180 MHz but the memory is unable to support FSB frequencies that exceed 150 MHz, you are limited to the FSB frequency of 150 MHz. For this reason, overclocking strongly depends on the quality of the memory modules. There are two main ways of overcoming the limited capabilities of memory overclocking. First, by tuning the BIOS settings, it is possible to change the ratio between the FSB frequency and the memory frequency, making the frequency of the memory bus as small as possible. Because overclocking results in a proportional [bookmark: 88][bookmark: IDX-35]increase of the FSB and memory frequencies, it is possible to create conditions under which the processor is overclocked to higher frequencies than the memory. Suppose that the system is designed to run at an FSB frequency of 133 MHz and to use DDR266 memory modules. This means that 266 MHz is the nominal frequency for the memory. If you specify the coefficient that relates the FSB and memory frequencies as 1.5, then, at an FSB frequency equal to 133 MHz, the memory frequency will be 200 MHz. This will be below the nominal value. When you overclock the FSB frequency to 177 MHz, the processor also will be overclocked, and the memory will operate at its nominal frequency of 266 MHz. This method of artificially slowing the memory is used quite frequently. However, it has drawbacks: When the maximum FSB frequency is reached, the memory still may run at a frequency below the nominal value. For example, suppose that you have an Intel Pentium 4 processor with a nominal frequency of 2.4 GHz (and a multiplier value of 18x). The nominal value of the FSB frequency is 133 MHz, and your computer is equipped with DDR266 memory modules. If the coefficient that relates the memory and FSB frequencies is set to 1.5, you might manage to overclock the FSB frequency to 160 MHz. In this case, the CPU clock frequency will be calculated as follows: 160 MHz × 18x = 2.88 GHz. (This is not a bad result.) However, the memory will operate at a frequency calculated as follows: 160 MHz × 1.5 = 240 MHz (i.e., below its nominal frequency). Which is better — to raise the CPU clock frequency and decrease the memory frequency, or to try to overclock both the CPU and RAM? This example that synchronizes the CPU and memory operations is not an artificial one. Overall system performance depends on the CPU and memory frequencies. Thus, true overclocking means finding optimal values. The conditions that provide a maximum increase in overall system performance often have to be defined experimentally. Another popular method uses faster memory than recommended in the motherboard specification. For example, DDR333 or even DDR400 memory modules can be used with motherboards supporting DDR266/200 memory. If you combine both approaches, you can achieve high FSB frequencies without being limited by the memory capabilities. In addition to frequency, other important parameters influence memory performance. These are memory timings. In most cases, tuning these will achieve significant performance gain. These will be covered in more detail in the appropriate sections of this book. For the moment, however, it is necessary to make some important notes. Before you start processor overclocking, it is necessary to improve the cooling system. You should correctly install the cooler and the heatsink. At first, it may [bookmark: 89][bookmark: IDX-36]seem that there are no difficulties here, but this impression is wrong. To achieve adequate cooling, a layer of thermal paste usually is placed between the surfaces of the processor and heatsink. The only exception is the so-called box coolers, included with the kits supplied by CPU manufacturers. [bookmark: 90][bookmark: ch03fig12][bookmark: IMG_22][image: Click To expand] Figure 3.12: Box kit comprising a CPU and cooler [bookmark: 91][bookmark: ch03fig13][bookmark: IMG_23][image: Click To expand] Figure 3.13: Box cooler Such coolers have a special heat-insulation layer; therefore, they do not require thermal paste. In all other cases, thermal paste is a must. If there is not enough thermal paste (for example, the CPU surface isn't covered entirely), or if the paste has been dried up, you must remove the paste using a special dissolvent and apply a new layer. Never try to scratch off the paste with the knife; scratches on the surface of the heatsink or CPU will degrade heat dispersion. The new layer of thermal paste must be distributed evenly over the entire surface of the CPU cover. This layer [bookmark: 92][bookmark: IDX-37]mustn't be too thick; a heavy layer also would degrade heat dispersion. The optimal thickness of the layer is 0.5 mm. You should consider purchasing a high-quality heatsink with a turbo-cooler. Box coolers usually are not intended for extreme modes. They do allow moderate overclocking, because box coolers have some power reserve. Besides this, it is necessary to consider installing an extra cooler into the system unit. Although this will make the computer a little noisy, it will improve the efficiency of the cooling system considerably. The right choice of motherboard also is of great importance. Its design, manufacturing quality, and used components must guarantee stable operation at high frequencies. Built-in tools, as well as BIOS, must support overclocked modes. The ability to change the following is standard: FSB frequency Coefficient relating the memory and FSB frequencies Memory timings Processor and memory core supply voltage Different manufacturers have different opinions about the overclocking problem. For example, on most Intel motherboards, this capability is locked. Other leading motherboard manufacturers, such as Abit, Asus, Gigabyte Technology, and MSI Computer, not only enable their users to change the previously listed standard settings, but they welcome the overclocking capability. Some manufacturers even include special overclocking utilities with their motherboards. The advantage of special utilities used for system overclocking is that main settings are changed programmatically, rather than via traditional methods such as BIOS or special switches on the motherboard. Usually, this takes place when the operating system is up and running. As a result, it is not necessary to reboot the computer after each change is introduced — provided that the system operates reliably and remains stable. Otherwise, reboot is inevitable. The functional abilities of such programs partially duplicate BIOS. Despite this, BIOS often provides a richer set of functionality, such as memory timing settings. However, special utilities significantly reduce the time required for system overclocking. Programs that support several motherboards can be purchased separately. In concluding this section, it is necessary to mention that the final result of overclocking strongly depends on the quality of the components used. It also depends on the overclocker's skills and experience. The examples of extreme overclocking confirm this statement. [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch03] [bookmark: 93][bookmark: ch03lev1sec3]Extreme Overclocking of Processors [bookmark: 94][bookmark: IDX-38] For extreme overclocking of processors, characterized by extremely high values of clock frequencies, it is often necessary to increase the core supply voltage considerably. These processes are accompanied by exceedingly high heat emission. If the heat is never dispersed from the processor chip, the heat balance required for correct operation of the core will be disrupted. Furthermore, the uneven workloads on internal structures and units of the processor, as well as their different operating frequencies, make the heating and heat emission of different core areas uneven. High temperatures of specific internal structures of the CPU chip limit the range of clock frequency growth. Besides this, high temperatures speed up semiconductor decay, which greatly reduces the processor durability. In addition, the processor becomes less stable, which influences overall system stability. Undesirable processes, even those that take place in recommended operating modes, significantly increase and speed up in extreme overclocking modes. A powerful and efficient cooling system can help to withstand some decay in semiconductors. Such a cooling system can ensure acceptable conditions for the processor operation, even in the course of extreme overclocking. Under conditions of extreme overclocking, the heat emission of the processor is so high that heat balance based on air-cooling support becomes inadequate. Liquid-cooling systems based on water are also unable to solve this problem. Water has the highest heat capacity of the natural substances that remain liquid in temperatures acceptable for semiconductors. Using water for cooling under normal conditions, including moderate overclocking, ensures efficient heat transmission from the hot chip to the heatsink equipped with a fan. Still, even a water-cooling solution cannot ensure the temperature required for extreme overclocking. The inefficiency of traditional cooling methods in extreme overclocking modes is related to the overheating of the internal circuitry of the processor chip. Extra heat emitted from these areas likely will disrupt the operation of complex semiconductor circuits. Local overheating can even destroy these circuits. Under these conditions, semiconductors are unable to function. Traditional cooling facilities cannot always evacuate this heat efficiently, especially because of the limited thermal conductance of silicon (or any other material). However, the value of heat flux, defined as the amount of heat passed per time unit, is proportional to the temperature gradient: [image: ] [bookmark: 95][bookmark: IDX-39] This means that the rate of heat transfer depends on the temperature difference between the heating zone and cooling zone. To ensure efficient cooling under conditions of extreme overclocking, it is best to use cryogenic temperatures at the surface of the cooled chip. Normal ice can be used as cooling substance; melting heat — the energy produced by a transition from a solid state to a liquid state — is rather high. This circumstance ensures that relatively little ice will be needed during experiments. However, its melting temperature is only 0°C (32°F), which doesn't ensure high values of heat flux. Ice can be used in experiments in the field of extreme overclocking, but it is unlikely that high results would be achieved in such experiments. The best temperature parameters are characteristic for so-called dry ice, or solid-state carbon oxide. Its temperature of phase transition is -70°C (-94°F). This, compared to normal ice, ensures far better values of heat flux. However, for carbon oxide, the temperature of phase transition into the gaseous state is much lower than the melting temperature of normal ice. This means more dry ice will be required for extreme overclocking experiments. Liquid nitrogen is a more promising cooling substance because its boiling temperature is close to -196°C (-320°F). However, its phase-transition energy is very low. As a result, the heat absorbed during evaporation of this substance is also very low. To cool powerful processors characterized by high values of heat generation, large amounts of liquid nitrogen will be required. Despite these difficulties, it was liquid nitrogen that allowed research groups in many countries to achieve good results in extreme overclocking of standard processors. Specific features and experimental results in the field of extreme overclocking of processors are provided in the following sections. [bookmark: 96][bookmark: ch03lev2sec1]Extreme Overclocking of Intel Processors (With the permission of http://www.overclockers.ru, a Russian-language Web site.) Liquid nitrogen has become the chosen cooling agent for extremely overclocked processors because it has an exceedingly low evaporation temperature. The large difference between the temperatures of evaporating nitrogen and the CPU surface produces an intensive heat exchange that efficiently cools the overclocked CPU. The use of liquid nitrogen required nonstandard facilities to play the role of processor cooler. To achieve this goal, researchers created a special container for nitrogen, installed on the top of the processor. This container was made from copper, the material with the best thermal conductance, after silver (which, unfortunately, is too expensive). [bookmark: 97][bookmark: IDX-40] The cooling container could have been manufactured by soldering (from sheet copper), drilling (one piece of copper), or welding. A stannic (tin) solder has never been recommended for such purposes, because standard solders of this type form unstable compounds at cryogenic temperatures. At temperatures below -40°C (-104°F), tin turns into mechanically unstable modification. Besides this, such a construction has lower thermal conductance than one manufactured from pure copper. This is because tin and its alloys have high thermal resistance. Another solution, which would require a container made from a solid piece of copper, was free from this drawback. Still, a large piece of expensive copper would be required, and most of this copper would be wasted. Furthermore, to manufacture this detail in such a way, special instruments would be required. Therefore, the third method was chosen. Elements of the container were joined using electron-beam welding. During this technological process, the parts to be connected were heated to the required temperature by the beam of electrons sped up to a high speed. The bond obtained using this method was rather strong. In addition, the residual stresses that remained in the material after the welding operation were minimal, which ensured high strength under drastic temperature changes and no geometric distortions of the cooling container due to geometrical skew. The dimensions of the cylindrical cooling container were chosen as follows: Height — 300 mm Diameter — 50 mm Thickness of walls — 2 mm Thickness of bottom — 3 mm This construction was installed on the processor and fastened using metal rods with screws and nuts. The container was pressed against the board using an additional plate of metal. This means that on one side, the rods were screwed into the motherboard, which has special holes for fastening coolers, and on the other side, they were fastened to the metallic plate that pressed the cooling container against the processor. The process of fastening this cooling system was as follows: The copper cooling container was installed on an Intel Pentium 4 processor. Metal rods with the appropriate screws were screwed into the holes in the motherboard and were fastened with nuts. From above, the container was pressed against the board using a plate of aluminum, which had a hole in the center and several holes for fastening rods at its sides. [bookmark: 98][bookmark: IDX-41] The rods were set into the holes, and the entire construction was fastened with nuts screwed from above. A funnel made of stainless steel was installed into the central hole. [bookmark: 99][bookmark: ch03fig14][bookmark: IMG_25][image: Click To expand] Figure 3.14: Cooling system for extreme processor overclocking (assembled) [bookmark: 100][bookmark: ch03fig15][bookmark: IMG_26][image: Click To expand] Figure 3.15: Filling the cooling system with liquid nitrogen After some time, a computer equipped with this cooling system stopped booting normally. The problem was related to condensation: A large amount of water accumulated near the processor slot. In the course of cooling, pieces of frozen condensate fell from the cooling container. On the motherboard, they melted [bookmark: 101][bookmark: IDX-42]and produced water. In other places on the motherboard, the water appeared because of the intense boiling of nitrogen, during which some drops fell on the motherboard. As a result, water appeared in cool regions of the motherboard. Ice crystals falling from the copper cooling container caused another serious problem. This problem was solved using a normal household fan. A stream of air, directed from this fan toward the cooling container, diverted all crystals that otherwise would have fallen on the motherboard. However, because the fan blew a large amount of air around the cooling container, it increased the thickness of the frost that covered the cooling container. This layer was rather dense, and it didn't fall onto the motherboard. As for the problem of water, it was solved by placing a sheet of foam rubber below the motherboard. [bookmark: 102][bookmark: ch03fig16][bookmark: IMG_27][image: Click To expand] Figure 3.16: Ice-crystal layer on the copper cooling container [bookmark: 103][bookmark: ch03fig17][bookmark: IMG_28][image: Click To expand] Figure 3.17: Motherboard covered with frost [bookmark: 104][bookmark: IDX-43] Later, another method was found to help solve the problem of condensation. The basic idea of this method was as follows: The entire motherboard was covered evenly with liquid nitrogen. As a result, the entire motherboard was cooled below the freezing point of water, and ice caused significantly less harm to the motherboard. These steps ensured stable operation of the system in the extreme overclocking mode of the processor. Of course, this could occur only if the cooling container contained liquid nitrogen and, consequently, if it ensured constant cooling of the processor. Configuration of the Test System Processors: Intel Celeron 1.8 GHz Intel Pentium 4 2.2 GHz Intel Pentium 4 2.4 GHz Intel Pentium 4 2.53 GHz Motherboard: Epox 4BDA RAM: Corsair XMS3000 Video adapter: VisionTek GeForce4 Ti4600 Software: Windows XP Professional/2000 Professional SP1 Nvidia Detonator 29.42 Researchers had to abandon thermal paste. At the temperature of liquid nitrogen, it would freeze. As a result, the CPU surface would be covered with a layer of ice, which would decrease heat exchange considerably. The cooling container also would freeze to the processor's surface. Therefore, a long time would be required to replace the processor. Because of this, a cooling container often was installed on a heat-dissipating plate, the Integrated Heat Spreader (IHS) of Intel Celeron and Intel Pentium 4 processors, without thermal paste. [bookmark: 105][bookmark: IDX-44] [bookmark: 106][bookmark: ch03fig18][bookmark: IMG_29][image: Click To expand] Figure 3.18: Frozen thermal paste on the heat-dissipating plate of the processor Extreme Overclocking of Celeron Processors Overclocking can be accomplished by increasing the FSB clock frequency while increasing the CPU core voltage (Vcore) to the maximum allowed by the motherboard. At a core voltage of 1.85 V, stable operation could be ensured at FSB frequencies to 140 MHz. This would result in a CPU frequency of 2,520 MHz (Fig. 3.19). [bookmark: 107][bookmark: ch03fig19][bookmark: IMG_30][image: Click To expand] Figure 3.19: Parameters of Intel Celeron 1.8 GHz overclocked to 2,519.91 MHz Several tests were performed for this mode. Test results obtained using SiSoftware Sandra are in Fig 3.20. [bookmark: 108][bookmark: IDX-45] [bookmark: 109][bookmark: ch03fig20][bookmark: IMG_31][image: Click To expand] Figure 3.20: Results of testing the overclocked CPU using SiSoftware Sandra [bookmark: 110][bookmark: IDX-46] Extreme Overclocking of Pentium 4 Processors Extreme overclocking of Intel Pentium 4 processors can be achieved by raising the FSB clock frequency at the core voltage of 1.85 V. As in the previous case, cooling was performed using liquid nitrogen. In the course of extreme overclocking, all CPU models exceeded the level of 3 GHz. The best result was achieved by the Intel Pentium 4 processor intended to run at 2.53 GHz. Being cooled by liquid nitrogen, this processor showed stable operation at a bus frequency of 185 MHz. Under conditions of the fixed multiplier value, this ensured the resulting clock frequency of 3,524 MHz. [bookmark: 111][bookmark: ch03fig21][bookmark: IMG_32][image: Click To expand] Figure 3.21: Parameters of Intel Pentium 4 2.53 GHz overclocked to the maximum frequency of 3,524.38 MHz In experiments on extreme overclocking using liquid nitrogen conducted by another group of researchers (see http://holicho.lib.net, a Japanese Web site), the Intel Pentium 4 processor intended to run at 3.06 GHz was successfully overclocked to 4.6 GHz. In these experiments, the FSB frequency equaled 200 MHz. Thus, one [bookmark: 112][bookmark: IDX-47]of the most powerful Intel processors implementing the NetBurst architecture, manufactured using 0.13-micrometer technology, was overclocked 1.5 times. In extreme overclocking experiments, researchers used the Gigabyte 8INXP motherboard based on the Granite Bay (E7205) chipset. To achieve high results, the CPU core voltage was increased to 2.1 V. Because the motherboard doesn't support such voltage levels, the voltage was raised using its hardware modification. [bookmark: 113][bookmark: ch03fig22][bookmark: IMG_33][image: Click To expand] Figure 3.22: Parameters of Intel Pentium 4 3.06 GHz overclocked to 4,599.85 MHz This example can be used to partially predict the performance of future processors with a clock frequency of 4.6 GHz and a bus frequency of 800 MHz. Such frequencies can be achieved only by the Prescott core, which has 1 MB of L2 cache memory manufactured using 0.09-micrometer technology. Note that Intel processors are not exceptions. A similar procedure of extreme overclocking is applicable to AMD products. Materials from a range of sites (see Chapter 19) serve as evidence of this. [bookmark: 114][bookmark: IDX-48] [bookmark: 115][bookmark: ch03lev2sec2]Extreme Overclocking of AMD Processors Extreme overclocking of AMD processors in systems with liquid nitrogen cooling has its own specific features. AMD products have no heat-dissipating plate similar to IHS on Intel processors; therefore, with AMD products, there is a high risk of causing mechanical damage to the core. Besides this, the lack of the even, smooth, and large area formed by heat-dissipating plate creates additional difficulties when ensuring even contact of the cooling container and the processor. On the other hand, the lack of this plate can have a positive effect on the cooling quality, because there will be only one transition (core — cooling container) instead of two transitions (core — IHS — cooling container). Extreme Overclocking of Athlon XP 1700+ Processors Well-known overclocker YAO (see http://www.piopioshardware.com, a Chinese Web site) accomplished extreme overclocking of the AMD Athlon XP 1700+ processor by increasing the multiplier and EV6 processor bus. The system operated at the following increased voltages: CPU core voltage (Vcore) North Bridge voltage (Vdd) RAM modules supply voltage (Vdimm) The processor was cooled using liquid nitrogen; for the North Bridge chip, water cooling was used. Configuration of the Test System Processor: AMD Athlon XP 1700+ (Marking = AXDA1700DLT3C JIUHB0309UPMW, clock frequency = 1,467 MHz, FSB frequency = 266 MHz, L2 cache = 256 KB, Vcore = 1.5 V) Motherboard: Epox EP-8RDA+, Rev.1.1, BIOS 3305 RAM: A-Data DDR400, 256 MB, 2.79 V (3-2-2-2.5 1CMD) × 2 [bookmark: 116][bookmark: IDX-49] Video adapter: Albatron MX420 (GeForce4 MX420) Hard disk: Quantum (20 GB, 7,200 rpm). Power supply unit: SevenTeam ST-300BLV Driver: Nvidia nForce Driver 2.3, Nvidia Detonator 42.86 As a result, the processor was overclocked to the frequency of 3,107 MHz, at a multiplier raised to 13x and a system bus frequency increased to 239 MHz. The voltage at the North Bridge chip was increased to 1.92 V using the hardware modification of the motherboard. RAM voltage was raised to 2.79 V; the CPU core voltage reached 2.016 V. [bookmark: 117][bookmark: ch03fig23][bookmark: IMG_34][image: Click To expand] Figure 3.23: Parameters of AMD Athlon XP 1700+ overclocked to 3,107.05 MHz [bookmark: 118][bookmark: IDX-50] [bookmark: 119][bookmark: ch03fig24][bookmark: IMG_35][image: Click To expand] Figure 3.24: Results of Dhrystone and Whetstone benchmark AMD Athlon XP 1700+ overclocked to 3,107.05 MHz [bookmark: 120][bookmark: IDX-51] [bookmark: 121][bookmark: ch03fig25][bookmark: IMG_36][image: Click To expand] Figure 3.25: Integer and floating-point results of testing AMD Athlon XP 1700+ overclocked to 3,107.05 MHz [bookmark: 122][bookmark: IDX-52] [bookmark: 123][bookmark: ch03fig26][bookmark: IMG_37][image: Click To expand] Figure 3.26: RAM results of testing AMD Athlon XP 1700+ overclocked to 3,107.05 MHz [bookmark: 124][bookmark: IDX-53] The performance of the AMD Athlon XP 1700+ processor overclocked to 3,107.05 MHz and cooled using liquid nitrogen can be evaluated according to the test results shown by SiSoftware Sandra. [bookmark: 125][bookmark: ch03table04] Table 3.4: Testing Results Shown by SiSoftware Sandra Tests Results for Athlon XP 1700+ (3,107.05 MHz) Results for Pentium 4 2.8 GHz Dhrystone ALU (MIPS) 11,640 8,196 Whetstone FPU (MFLOPS) 4,721 2,408 5,250 (SSE2) Integer aEMMX/aSSE (it/sec) 17,288 1,3090 (SSE2) Floating-point (it/sec) 18,236 1,9600 (SSE2) RAM integer buffered aEMMX/ aSSE bandwidth (MB/sec) 3,691 2,937 (SSE2) RAM floating-point buffered aEMMX/aSSE bandwidth (MB/sec) 3,520 2,940 (SSE2) As a result of extreme overclocking of the AMD Athlon XP 1700+ processor, its clock frequency (1,467 MHz) was increased 112% to 3,107 MHz. This corresponds to a rating of 4000+. To conclude, it is necessary to emphasize that the results of extreme overclocking provided here were achieved only because of the art of overclockers and researchers, who used cryogenic cooling. These systems and methods are not suitable for home usage. Nevertheless, these data are interesting; they demonstrate the potential of modern computer technologies. The results provided in these experiments can be used to predict the potential of future products. [bookmark: 126][bookmark: IDX-54] [image: Previous Section] < Day Day Up > [image: Next Section] [image: Previous Section] < Day Day Up > [image: Next Section] [bookmark: ch04] Chapter 4: Main Components and the Optimal Choice [bookmark: 128][bookmark: IDX-55] The main computer hardware components are the processor, RAM, video adapter, motherboard, and hard disk. The entire system configuration depends on the components chosen. Functional capabilities of the computer and overall system performance in both nominal and overclocked modes depend on the properties of these components and the efficiency of their operation. Depending on the configuration, the components supplied by different manufacturers might have different parameters and properties. Accounting for specific features allows you to choose the optimal configuration, based on financial limitations and planned tasks. [bookmark: 129][bookmark: ch04lev1sec1]Processors The processor is a central element of any computer system. Currently, the most popular and widely used processors are the ones manufactured by Intel (which holds more than 75% of the market) and AMD. Besides these market leaders, another large manufacturer of processors for PCs is Via Technologies. [bookmark: 130][bookmark: ch04lev2sec1]Intel Pentium III/Celeron (Coppermine) Intel Pentium III processors with the Coppermine core were based on experience accumulated by developing and running Pentium II, Pentium III, and Celeron (Mendocino). [bookmark: 131][bookmark: IDX-56] The first representatives of the Pentium III processor line were released by the end of 1999. Pentium III processors based on the Coppermine core are manufactured using 0.18-micrometer technology. Similar to the earlier Pentium III processors based on the Katmai core, the successors support MMX and SSE. In contrast to their predecessors, they have an integrated L2 cache of 256 KB intended to operate at the core frequency. This makes them similar to the Celeron processors based on the Mendocino core. However, in Coppermine-based processors, L2 cache memory has become larger, the internal bus has been extended from 64 bits to 256 bits, the algorithm of operation has been enriched (256-bit Advanced Transfer Cache), and the core architecture has been improved. These factors allow the processor to achieve higher performance. Performance has improved not only in comparison to the overclocked Celeron (Mendocino) processors, but also in comparison to the Pentium III (Katmai) processors with 512 KB of cache memory, operating at the same frequencies. In the Pentium III (Coppermine) processor line, some models are intended to operate at the bus frequencies of both 100 MHz and 133 MHz. The latter have the B character in their marking, distinguishing them from processors intended to operate at a 100 MHz bus frequency. Models that have the same frequencies as Pentium III (Katmai) processors are labeled with the E character. As form factors, SECC2 (Slot 1) and FC-PGA (Flip Chip-Pin Grid Array) (Socket 370) were chosen. Gradually, processors designed using the Socket 370 standard have replaced their predecessors (Figs. 4.1–4.4). [bookmark: 132][bookmark: ch04fig01][bookmark: IMG_38][image: Click To expand] Figure 4.1: Pentium III processor with the SECC2 (Slot 1) form factor, heatsink, and fan [bookmark: 133][bookmark: IDX-57] Note that all Pentium III (Coppermine) processors have a fixed multiplier that relates internal and external frequencies; therefore, overclocking can occur only if the processor bus (external) frequency is increased. Many of the first models of this processor line, intended for a 100 MHz bus frequency, easily allowed the Front Side Bus (FSB) frequency to be increased to 133 MHz or further. Pentium III (Coppermine) processors have repeated the success of their predecessors. Their overclocking potential confirms that processors of this type have significant technological reserve. This reserve allows both external and internal frequencies to be increased considerably. This increase is accompanied by processor performance growth and, consequently, an increase in overall system performance. [bookmark: 134][bookmark: ch04fig02][bookmark: IMG_39][image: Click To expand] Figure 4.2: Slot 1 processor slot [bookmark: 135][bookmark: ch04fig03][bookmark: IMG_40][image: Click To expand] Figure 4.3: Pentium III processor with the FC-PGA (Socket 370) form factor [bookmark: 136][bookmark: IDX-58] [bookmark: 137][bookmark: ch04fig04][bookmark: IMG_41][image: Click To expand] Figure 4.4: Socket 370 processor slot To provide a more precise evaluation of the temperature mode and appropriate selection of cooling devices, the data on the thermal power dissipated by Pentium III Katmai (512KB L2) and Coppermine (256KB L2) processors are provided in Tables 4.1–4.3. [bookmark: 138][bookmark: ch04table01] Table 4.1: Pentium III Heat Dissipation (256KB L2, SECC2) Processor model Maximum thermal power (W) 533EB