Notes For Sections 5.2 And 5.3; Start/Stop Time - Seagate ST12400N Product Manual

Product Manual - Hawk 2 Family SCSI-2 (Volume 1), Rev. C
_________________________________________________________________________________________
5.3.1

Notes for sections 5.2 and 5.3.

[1] Execution time measured from receipt of the last Byte of the Command Descriptor Block (CDB) to the re-
quest for a Status Byte Transfer to the Initiator (excluding connect/disconnect).
[2] Maximum times are specified over the worst case conditions of temperature, voltage margins and drive
orientation. When comparing specified seek times, care should be taken to distinguish between typical seek
times and maximum seek times. The best comparison is obtained by system benchmark tests conducted
under identical conditions. Maximum times do not include error recovery.
[3] Typical Seek values are measured under nominal conditions of temperature, voltage, and horizontal orienta-
tion as measured on a representative sample of drives.
[4] Assumes no errors and no sector has been relocated.
[5] Rate measured from the start of the first sector transfer to or from the Host.
[6] Assumes the Initiator immediately sends Write Data to the drive when requested.
[7] Command execution requires a data transfer phase (data to or from the disc media). Assumes the initiator is
instantly ready to send/receive the data when the drive generates first request for a data byte transfer, and
assumes an average data transfer rate between the drive and the Initiator as specified in section 5.3.
[8] All performance characteristics assume that automatic adaptive temperature compensation is not in process
when the SCSI command is received. A SCSI command being executed is not interrupted for automatic
adaptive temperature compensation. If adaptive thermal compensation is in process when a SCSI command
is received, the command is queued until the compensation for the specific head being compensated com-
pletes. When compensation completes for the specific head being compensated, the first queued SCSI
command is executed. When execution of the first queued command is complete, the drive continues the
compensation for the remaining head(s). The above procedure continues until compensation for all heads is
completed, or until one minute has elapsed. If the compensation for all heads is not complete in one minute,
the drive performs compensation for all of the remaining heads sequentially without any interruption. The
drive initiates an automatic adaptive temperature compensation cycle approximately one minute after power-
on, and approximately once every 10 minutes thereafter. Automatic adaptive temperature compensation
takes less than 0.1% of bus time. Automatic temperature compensation also 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). A Rezero command can be used to reset the thermal com-
pensation timer back to its start so that the host can know when the interruption for thermal compensation will
occur.
5.4

Start/stop time

After DC power has been applied, the drive becomes ready within 25 seconds if the Motor Start Option is dis-
abled (i.e. the motor starts as soon as the power has been applied). During this time the drive responds to some
commands over the SCSI interface*. Stop time is less than 20 seconds from removal of DC power.
11