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7K200 SATA OEM Specification
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4.4.2
Mechanical positioning
4.4.2.1 Average seek time (including settling)
Command Type
Typical (ms)
Max. (ms)
Read 10
16
Write 11
17
Table 5. Mechanical positioning performance
Typical and Max. are defined throughout the performance specification as follows:
Typical
Average of the drive population tested at nominal environmental and voltage conditions.
Max.
Maximum value measured on any one drive over the full range of the environmental and
voltage conditions. (See section 6.1, "Environment" on page 26 and section 6.2, "DC power
requirements" on page 28)
voltage conditions. (See section 6.1, "Environment" on page 26 and section 6.2, "DC power
requirements" on page 28)
The seek time is measured from the start of motion of the actuator to the start of a reliable read or write
operation. A reliable read or write operation implies that error correction/recovery is not employed to
correct arrival problems. The Average Seek Time is measured as the weighted average of all possible
seek combinations.
operation. A reliable read or write operation implies that error correction/recovery is not employed to
correct arrival problems. The Average Seek Time is measured as the weighted average of all possible
seek combinations.
max.
Σ (max. + 1 – n)(Tn
in
+ Tn
out
)
n=1
Weighted Average = ––––––––––––––––––––––––––––
(max.
(max.
+
1)(max)
Where: max.
= maximum seek length
n = seek length (1-to-max.)
Tn
Tn
in
= inward measured seek time for an n-track seek
Tn
out
= outward measured seek time for an n-track seek
4.4.2.2 Full stroke seek
Command Type
Typical (ms)
Max. (ms)
Read 18.0 30.0
Write 19.0 31.0
Write 19.0 31.0
Table 6. Full stroke seek time
Full stroke seek time in milliseconds is the average time of 1000 full stroke seeks.
4.4.2.3 Single track seek time (without command overhead, including
settling)
Command Type
Typical (ms)
Maximum (ms)
Read 1.0 4.0
Write 1.2 4.5
Table 7. Single track seek time
Single track seek is measured as the average of one (1) single track seek from every track in both
directions (inward and outward).
directions (inward and outward).
4.4.2.4 Average latency
Rotational Speed
(RPM)
Time for one revolution
(ms)
Average Latency
(ms)
7200 8.3
4.2
Table 8. Latency time