Product manual

10 Barracuda 9 Product Manual, Rev. C
SCSI interface data transfer rate (asynchronous) [4]:
Maximum instantaneous 5.0 Mbytes/sec [5]
Maximum average 10.0 Mbytes/sec [6]
Synchronous transfer rate for SCSI Fast-20 (Ultra SCSI) 2.5 to 20 Mbytes/sec
(8 bit data bus models)
Synchronous transfer rate for SCSI Fast-20 (Ultra SCSI) 5.0 to 40 Mbytes/sec
(16 bit data bus models)
Synchronous transfer rate for fast SCSI-2 1.25 to 10 Mbytes/sec
(8 bit data bus models)
Synchronous transfer rate for fast SCSI-2 2.5 to 20 Mbytes/sec
(16 bit data bus models)
Sector sizes:
Default 512-byte data blocks
Variable in even-sector sizes 180 to 4,096 bytes per sector
Read/write consecutive sectors on a track Yes
Flaw reallocation performance impact (for flaws
reallocated at format time using the spare tracks per
volume reallocation scheme) 35 msec (typical)
Overhead time for head switch (512-byte sectors)
in sequential mode 0.8 msec
Overhead time for one track cylinder switch
in sequential mode 1.2 msec (typical)
Average rotational latency 4.17 msec
Notes for Sections 4.2.
[1] Execution time is 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. These access times do not include average
rotational latency time.
[3] Assumes no errors and no sector reallocations.
[4] Rate measured from the start of the first sector transfer to or from the host.
[5] Assumes system ability to support the rates listed 1 byte wide and no cable loss.
[6] Assumes system ability to support the rates listed 2 bytes wide and no cable loss.
[7] Access time = controller overhead + average seek time.
Access data time = controller overhead + average seek time + latency.