Seagate ST15150DC, Product Manual

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ST15150N/ND/W/WD/WC/DC Product Manual, Rev. D 11
5.0 Performance characteristics
This section provides performance-related characteristics and features of
Barracuda 4 drives.
5.1 Internal drive characteristics
Drive capacity, Mbytes unformatted 5,062
Read/write data heads, maximum (physical) 21
Bytes per track, average bytes 64,160
Bytes per surface, Mbytes unformatted 232.4
Cylinders/tracks per surface, user accessible 3,711
Tracks per inch 4,048
Bits per inch 73,820
Servo heads 1
Internal data rate per physical head, Mbits/sec, 47.5 to 72.0
variable with zone
Disc rotation speed 7,200
±
0.5%
Avg rotational latency, msec 4.17
5.2 SCSI seek performance characteristics
ASA I download code thermal calibration (TCAL)
All performance characteristics assume that thermal calibration is not in
process when the drive receives the SCSI command. Thermal calibration
will not interrupt an active SCSI command. If thermal calibration is in
process when a SCSI command is received, the command is queued until
the calibration for the specific head being calibrated completes. When
calibration completes for the specific head being calibrated, the first queued
SCSI command executes. When execution of the first queued command is
complete, the drive continues the calibration for the remaining head.
The above procedure continues until calibration for all heads has com-
pleted, or until 10 minutes have elapsed. The drive initiates a thermal
calibration cycle once on power-up before completing its initialization
sequence and then once after 1 minute from the end of initialization. After
this, the drive initiates thermal calibration cycle approximately once every
10 minutes. Automatic non-interruptible thermal calibration occurs at
other times but should be transparent to the user (e.g., during format,
Rezero command, at spindle-up, during read error recovery, and during
reassign block functions). You can use the Rezero command to reset the
thermal calibration timer back to its start so that the host knows when the
interruption for thermal calibration will occur.