Mass Storage Devices
By having the hard drive as the source of both the strobe and the data during a read, Ultra ATA/33
eliminated both propagation and data turnaround delays. The elimination of these delays improved the
timing margins. Ultra ATA/66 retains the same strobe frequency but doubles the burst transfer rate once
again.
Ultra ATA/66 is available on HP PCs and e-pcs running Windows 98, Windows NT4 and Windows 2000.
Ultra ATA/66 is not available with Windows 95.
The progressive advantage of Ultra ATA/66 is to double the transfer rate once again, this time by
reducing setup times. Timing signals are made twice as fast. However, a new 80-conductor cable is
needed to ensure data integrity. The 40-pin interface cable of the earlier Ultra ATA/33 and multi-word
DMA interfaces cannot handle the shorter cycle times for a 44.4MB/s or 66.6MB/s burst rate. The 80-
conductor cable retains the same connector configuration as the standard 40-pin interface cable but has
ground lines interleaved between all signal lines. In other words, the 40 new lines are all ground (which
act as shields) and no new signals are transferred.
Ultra ATA/33 introduced CRC, a feature new to IDE that provides data protection verification. Ultra
ATA/66 uses the same process. The CRC is calculated on a per-burst basis by both the host and the hard
drive, and is stored in their respective CRC registers. At the end of each burst, the host sends the
contents of its CRC register to the hard drive, which then compares it against its own register’s contents.
If the hard drive reports errors to the host, then the host retries the command containing the CRC error.
Ultra ATA/100
Ultra ATA/100 is an extension of the Ultra ATA/66 hard drive interface. Ultra ATA/100 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 100MB/s. This is considerably
faster than the 66.6MB/s data transfer speeds of Ultra ATA/66. The result is maximum disk performance
under PCI local bus environments.
At its fast burst data rates, Ultra ATA/100 will go farther than Ultra ATA/66 in removing 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. As with Ultra ATA/66, CRC ensures the integrity of transferred data
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 100 percent backwards compatible with Ultra ATA/66, Ultra ATA/33, and
DMA, as well as with existing EIDE/IDE hard drives, CD-ROM drives, and host systems.
NOTE
S.M.A.R.T. or Self Monitoring Analysis and Reporting Technology allows the hard disk 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.
hp business pc technology 39

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Ce manuel est également adapté pour les modèles :
Ordinateurs - HP e-PC c10/s10 (412.39 kb)
Ordinateurs - Compaq 100B Small Form Factor PC (412.39 kb)