IBM Ultrastar 36LZX, Specifications

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4.5.2 Mechanical positioning
4.5.2.1 Average seek time (including settling)
6.9 [msec] 5.9 [msec] Write
5.9 [msec] 4.9 [msec] Read
Max Typical Command Type
Figure 7. Mechanical positioning performance
“Typical” and “Max” are given throughout the performance specification by:
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
Environment on page 38 and DC power requirements on
page 40 for ranges.)
The seek time is measured from the start of the actuator's motion to the start of a reliable read or write
operation . “Reliable read or write” implies that error correction/recovery is not used to correct arrival
problems. The average seek time is measured as the weighted average of all possible seek
combinations.
Weighted average =
(max+1) (max)
max
Sum
n=1
(max+1-n) (Tn.in+Tn.out)
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
4.5.2.2 Full stroke seek time
12.5 [msec] 11.5 [mesc] Write
11.5 [msec] 10.5 [msec] Read
Maximum Typical Function
Figure 8. Full stroke seek time
Full stroke seek is measured as the average of 1000 full stroke seeks with a random head switch from
both directions (inward and outward).
Ultrastar 36LZX hard disk drive specifications
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