Seagate ST15150N Product Manual - Page 21

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 Tracks per inch 3,711 4,048 Bits per inch 73,820 Servo heads 1 Internal data rate per physical head, Mbits/sec, variable with zone Disc rotation speed Avg rotational latency, msec 47.5 to 72.0 7,200 ± 0.5% 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 completed, 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.