  In today's marketplace, the cost per Terabyte of disks with EIDE interfaces
is about a third that of disks with SCSI. Hence, three times as many particle
physics events could be put online with EIDE. The modern EIDE interface
includes many of the performance features that appeared earlier in SCSI. EIDE
bus speeds approach 33 Megabytes/s and need only be shared between two disks
rather than seven disks. The internal I/O rate of very fast (and expensive)
SCSI disks is only 50 per cent greater than EIDE disks. Hence, two EIDE disks
whose combined cost is much less than one very fast SCSI disk can actually give
more data throughput due to the advantage of multiple spindles and head
actuators. We explore the use of 12 and 16 Gigabyte EIDE disks with motherboard
and PCI bus card interfaces on a number of operating systems and CPUs. These
include Red Hat Linux and Windows 95/98 on a Pentium, MacOS and Apple's
Rhapsody/NeXT/UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10
workstation.
