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1.6 Seek time
Seek time is the interval between the time the actuator begins to move
and the time the head has settled over the target track. Seek time is a
statistical average of at least 10,000 measurements of seek time. All
measurements for maximum values are taken under nominal conditions
of temperature and voltage with the drive mounted horizontally. The
specifications in the table below are defined as follows:
• Track-to-track seek time is the average of all possible single-track
seeks in both directions.
• Average seek time is measured by executing seeks in both directions
between random cylinders.
• Full-stroke seek time is half the time needed to seek from track 0 to
the maximum track and back to track 0.
Track-to-track
Average/typical
seek time
seek time
3.5 msec typ
12 msec read
4.5 msec max
14 msec write
Note. Host overhead varies between systems and cannot be specified.
Drive internal overhead is measured by issuing a no-motion seek.
Overhead is typically less than 0.5 msec.
1.7 Start and stop times
The drive is ready within 20 seconds after the power is applied. The drive
spindle stops rotating within 15 seconds after the power is removed.
1.8 Typical power-up and power-down sequence
A typical power-up and power-down sequence is described below to
assist you in evaluating the drive's performance. It is not a performance
specification. Each drive has a unique startup current profile similar to
Figure 1.
Decathlon 850 ATA Product Manual, July 1995
Full-stroke
seek time
25 msec typ
27 msec max
Average
latency
5.56 msec
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