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10
SCSI interface data transfer rates (asynchronous):
Maximum instantaneous 8 bit wide
Maximum instantaneous 16 bit wide
Synchronous formatted transfer rates:
In SCSI Wide (16 bit)
Sustainable data transfer rates:
Minimum
Average
Maximum
Sector Sizes:
Default
Variable
Read/write consecutive sectors on a track
Flaw reallocation performance impact (for flaws reallocated at format
time using the spare sectors per sparing zone reallocation scheme.)
Average rotational latency
Notes for Section 4.2.
[1]
Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the
request for a Status Byte Transfer to the Initiator (excluding connect/disconnect).
[2]
Typical access times are measured under nominal conditions of temperature, voltage, and horizontal ori-
entation as measured on a representative sample of drives.
[3]
Assumes no errors and no sector has been relocated.
[4]
Assumes system ability to support the rates listed and no cable loss.
[5]
Access time = controller overhead + average seek time.
Access to data = controller overhead + average seek time + latency time.
[6]
Drive required to be in LVD mode to attain maximum transfer rates.
4.3
Start/stop time
After DC power at nominal voltage has been applied, the drive becomes ready within 20 seconds if the Motor
Start Option is disabled (i.e. the motor starts as soon as the power has been applied). If a recoverable error
condition is detected during the start sequence, the drive executes a recovery procedure which may cause the
time to become ready to exceed 20 seconds. During spin up to ready time the drive responds to some com-
mands over the SCSI interface in less than 1.5 seconds after application of power. Stop time is less than 15
seconds from removal of DC power.
If the Motor Start Option is enabled, the internal controller accepts the commands listed in the SCSI Interface
Product Manual less than 1.5 seconds after DC power has been applied. After the Motor Start Command has
been received the drive becomes ready for normal operations within 16 seconds typically (excluding an error
recovery procedure). The Motor Start Command can also be used to command the drive to stop the spindle
(see SCSI Interface Product Manual, part number 75789509).
There is no power control switch on the drive.
4.4
Prefetch/multi-segmented cache control
The drive provides prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. "Cache" as used herein refers to the drive buffer storage space when
it is used in cache operations. To select prefetch and cache features the host sends the Mode Select command
with the proper values in the applicable bytes in Mode Page 08h (see SCSI Interface Product Manual, part
number 75789509). Prefetch and cache operation are independent features from the standpoint that each is
5.0 Mbytes/sec [4]
10.0 Mbytes/sec [4]
Ultra2 SCSI
10.0 to 80 Mbytes/sec
39 Mbytes/sec
47 Mbytes/sec
51 Mbytes/sec
512 byte user data blocks
512 to 4,096 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.
Cheetah 36ES Product Manual, Rev. A
Ultra160 SCSI
10.0 to 160 Mbytes/sec [6]
Yes
Negligible
2.99 msec
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