Ultra-Ata/100 Hard Drives - Compaq Evo D510 e-pc Technical Reference Manual

Ultra-ATA/100 Hard Drives

ATA (AT Attachment) is a disk drive implementation designed to integrate the controller into the
drive itself, thereby reducing interface costs. ATA is also known as IDE (Integrated Drive
Electronics).
Ultra ATA/100 is the latest generation of the ATA interface, it increases burst data rates
significantly over previous versions of the protocol. Also known as Ultra DMA/100 and
Feature ATA, Ultra ATA/100 allows host computers to send and receive data at 100 MB/s. The
result is maximum disk performance under PCI local bus environments.
At its fast burst data rates, Ultra ATA/100 removes bottlenecks associated with data transfers,
especially during sequential operations. Ultra ATA/100 also delivers heightened data integrity to
the EIDE interface through use of a 40-pin 80-conductor cable, and CRC (Cyclic Redundancy
Check) error detection code. The 80-conductor cable reduces crosstalk and improves signal
integrity by providing 40 additional ground lines between the 40-pin IDE signal and ground
lines. The connector is plug-compatible with existing 40-pin headers, and the incremental cost
for the cable should be minimal.
By increasing the burst transfer rates of IDE drives, Ultra ATA/100 brings the effective transfer
rate of the system's bus and a drive's internal data rate that much closer into balance. Ultra
ATA/100 allows greater system throughput, particularly for long sequential transfers required by
audio/visual applications.
Ultra ATA/100 hard drives are backwards compatible with earlier devices but will take on the
speed of earlier devices when used in their stead.
✎
S.M.A.R.T. or Self Monitoring Analysis and Reporting Technology allows the hard drive to
report certain types of degradation or impending failure. This allows the operating system to take
the necessary precautions and warn the user. The system is comprised of software that resides
both on the disk drive and on the host computer. The disk drive software monitors the internal
performance of the motors, media, heads, and electronics of the drive, while the host software
monitors the overall reliability status of the drive. The reliability status is determined through the
analysis of the drive's internal performance level and the comparison of internal performance
levels to predetermined threshold limits.
Technical Reference Guide
System Features
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