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12 Cheetah 15K.4 FC Product Manual, Rev. B
4.2.2 Format command execution time (minutes)
4.2.3 General performance characteristics
4.3 Start/stop time
If the Motor Start option is disabled, the drive becomes ready within 20 seconds after DC power is applied. If a
recoverable error condition is detected during the start sequence, the drive executes a recovery procedure and
the time to become ready may exceed 20 seconds. Stop time is 30 seconds (maximum) from removal of DC
power.
If the Motor Start option is enabled, the internal controller accepts the commands listed in the Fibre Channel
Interface Manual less than 3 seconds after DC power has been applied. After the Motor Start command has
been received, the drive becomes ready for normal operations within 20 seconds (excluding the error recovery
procedure). The Motor Start command can also be used to command the drive to stop the spindle.
There is no power control switch on the drive.
4.4 Prefetch/multi-segmented cache control
The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in
cache operations. To select this feature, the host sends the Mode Select command with the proper values in
ST3146954FC ST373554FC ST336854FC
Maximum (with verify)
90 60 30
Maximum (without verify)
45 30 15
Data buffer to/from disc media (one 512-byte logical block)*
Minimum 685 Mbits/sec
Maximum 1,142 Mbits/sec
Fibre Channel Interface maximum instantaneous transfer rate 200 Mbytes/sec* per port
(dual port = 400 Mbytes/sec*)
Logical block sizes
Default is 512-byte data blocks
Variable 512 to 704 bytes per sector in even number of bytes per
sector. If n (number of bytes per sector) is odd, then n-1 will be used.
Read/write consecutive sectors on a track Yes
Flaw reallocation performance impact (for flaws reallocated at format time
using the spare sectors per sparing zone reallocation scheme.)
Negligible
Average rotational latency 2.0 msec
*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or
from the host.