System Upgrading and Optimizing
This article covers the following objective in the "Domain 1.0: Installation, Configuration, and Upgrading" section of the A+ Certification exam:
1.8: Identify hardware methods of upgrading system performance, procedures for replacing basic subsystem components, unique components and when to use them.
The modular design of the PC-compatible system enables portions of the system to be upgraded, as new or better components become available or as the system's application changes. As this A+ objective points out, computer technicians must be able to upgrade the system's Basic Input Output System (BIOS) as part of a system upgrade. Technicians should also be able to optimize PC hardware to get the best performance possible for a given system configuration.
System Board Upgrading
There are typically five serviceable components on the system boar
The RAM modules
The CMOS backup battery
The ROM BIOS integrated circuit (IC)
The cache memory
Of these five items, three—the microprocessor, the RAM modules, and the cache memory—can be exchanged to increase the system's performance. These devices are normally mounted in sockets to make replacing or upgrading them an easy task.
Take great care when exchanging these parts to avoid damage to the ICs from electrostatic discharge (ESD). (For more information on ESD prevention, see InformIT's article "Electrostatic Discharge Precautions" by Charles J. Brooks.) In addition, take care when extracting and replacing ICs to avoid misalignment and bent pins. Make sure to correctly align the IC's pin 1 with the socket's pin 1 position.
Microprocessor manufacturers have devised upgrade versions for virtually every type of microprocessor in the market. It is also common for clone microprocessors to be pin-for-pin compatible with older Intel socket designs. This strategy enables the end user to realize a speed increase by upgrading, along with an increase in processing power.
Upgrading the processor is a fairly easy operation after gaining access to the system board. Just remove the microprocessor from its socket and replace it with the upgrade. Set the system's Voltage and Bus Ratio configuration jumpers to the correct settings for the processor being installed. You can find these settings in the system board's installation manual.
Two items must be observed when changing the microprocessor:
Make sure the replacement microprocessor is hardware compatible with the original; otherwise, the system board will not support the new microprocessor type.
Make certain to properly orient the new processor in the socket so that its pin 1 matches the socket's pin 1.
The physical upgrade should also be accompanied by a logical upgrade. When the microprocessor is upgraded, the BIOS should also be upgraded. In newer system boards, this can be accomplished by flashing (electrically altering) the information in the BIOS with the latest compatibility firmware. If the BIOS does not have the Flash option and does not support the new microprocessor, you will need to get an updated BIOS IC from the manufacturer that is compatible with the new processor and the system board's chipset. Make certain to record your CMOS configuration information before flashing or changing the BIOS device. This will permit you to reinstall those settings on the updated BIOS.
Know what precautions to take before upgrading the system's BIOS.
Upgrading system board memory is also a fairly simple process. Having more RAM onboard allows the system to access more data from extended or expanded memory, without having to access the disk drive. This speeds up system operation considerably. Normally, upgrading memory just amounts to installing new memory modules in vacant single in-line memory module (SIMM) or dual in-line memory module (DIMM) slots. If the slots are already populated, you must remove them to install faster or higher capacity modules.
Consult the system board's User Guide to determine what speed the memory devices must be rated for. You should be aware that RAM and other memory devices are rated in access time rather than clock speed. Therefore, a -70 nanosecond (ns) RAM device is faster than an -80 nanosecond device. The guide should also be checked for any memory configuration settings that must be made to accept the new memory capacity.
If the system has socketed cache memory, you can gain some additional performance by optimizing the cache. Upgrading the cache on these system boards normally requires only that additional cache ICs be installed in vacant sockets. If the sockets are full but the system's cache size is less than maximum, it will be necessary to remove the existing cache chips and replace them with faster, higher capacity devices. Make sure to observe the pin 1 alignment and check the system board's User Guide for any configuration jumper changes.
Before upgrading the system board's field replaceable unit (FRU), check the cost of the proposed component upgrade against the cost of upgrading the system board itself. In many cases, the RAM from the original board can be used on a newer, faster model that should include a more advanced microprocessor. Before finalizing the choice to install a new system board, however, make sure the current adapters, software, and peripherals will function properly with the updated board. If not, the cost of upgrading might be unexpectedly higher than just replacing an FRU component.