IBM IC25N040ATCS04 - Travelstar 40 GB Hard Drive, Specifications

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4.4.2 Mechanical positioning
4.4.2.1 Average seek time (including settling)
17 14 Write
16 12 Read
Max. (ms) Typical (ms) Command Type
Figure 9. Mechanical positioning performance
Typical and Max. are defined throughout the performance specification as follows:
Maximum value measured on any one drive over the full range of the environmental and
voltage conditions. (See section 6.1, "Environment" on page 23 and section 6.2, "DC power
requirements" on page 25) Max.
Average of the drive population tested at nominal environmental and voltage conditions. Typical
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 cor-
rect 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. + 1)(max)
Where: max. = maximum seek length
n = seek length (1-to-max.)
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
31.0 24.0 Write
30.0 23.0 Read
Max. (ms) Typical (ms) Command Type
Figure 10. Full stroke seek time
Full stroke seek time in milliseconds is the average time of 1000 full stroke seeks.
Travelstar 60GH & 40GN hard disk drive specifications
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