Ultra Ata/66 Hard Drives - HP Compaq SP750 Supplementary Manual

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Customer Benefits
Maximum burst rate is doubled. Ultra3 SCSI features a 160 MB per second burst rate,
compared to Wide Ultra2 SCSI' s 80 MB per second. This saves time through faster
performance in some applications where the SCSI bus is the bottleneck. In multiple disk
configurations, significant gains are evident where large blocks of data are sequentially
accessed.
Domain validation to verify system configuration (it ensures end-to-end cable configurations
operate correctly) and confirm the systems ability to run at negotiated speed. This reduces
Total Cost of Ownership (TCO) by minimizing emergency support calls involving
improperly designed or configured systems.
Enhanced data integrity
Support for up to seven SCSI devices

Ultra ATA/66 Hard Drives

The Ultra ATA interface was developed by Intel and Quantum and is commonly referred to as
UDMA, Ultra ATA, UATA, or simply ATA. Using "ATA" to refer to Ultra ATA can be
confusing. ATA was an earlier protocol with a burst data transfer rate of 16.5 megabytes per
second (MB/s). The first version of Ultra ATA, Ultra ATA/33, doubled the burst data transfer
rate to 33 MB/s without the need for other hardware changes and is, therefore, fully backward
compatible to ATA. Now there is Ultra ATA/66, which doubles the burst transfer rate again to
66 MB/s, and is still backward compatible to ATA. Ultra ATA/66 models implement legacy data
transfer protocols that allow them to work in legacy ATA PCs (at legacy ATA functionality).
Additionally, Ultra ATA controllers can support up to two devices. The Ultra ATA technology
also delivers improved data integrity through improved timing margins and Cyclical Redundancy
Check (CRC) data protection verification.
A significant benefit of an ATA hard drive from Compaq is the Drive Protection System (DPS), a
hard drive self-test, embedded in the hard drive firmware. Compaq initiated the concept of a
resident self-test to reduce the unnecessary replacement of hard drives. DPS offers customers an
advanced diagnostic tool designed to identify physical hard drive defects that could result in the
loss of data. DPS is unlike current system-level diagnostic tools, which have to be generic to
cover multiple suppliers' hard drives; DPS is a design-specific, drive-level test. Current
diagnostic tools are dependent on other system components (operating system, cables, CPU) to
operate successfully. DPS was derived from the existing SMART protocol and is now an
accepted industry standard. Upon execution, information obtained through DPS testing is
permanently recorded on the drive. This logging capability assists in troubleshooting system level
problems that might result in unwarranted hard drive replacement
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Compaq Professional Workstation - Key Technologies