USER RESPONSIBLE FOR VERIFYING VERSION AND COMPLETENESS
OEM FUNCTIONAL SPECIFICATION ULTRASTAR XP (DFHC) SSA MODELS 1.12/2.25 GB -1.0" HIGH
2.0 Specifications
All specifications are nominal values unless otherwise noted.
The Ultrastar XP SSA data storage capacities vary as a function of model and user block size. T he
emerging Industry trend is capacity points in 1.08GB (i.e. 1.08/2.16/4.32) at a block size of 512 b ytes. This
and future products will always plan to provide capacities that are consistent with this trend. Users that
choose to make full use of th e Ultrastar XP SSA drive capacity above the standard capacity p oints may not
find equivalent capacity breakpoints in future products.

2.1 General

Note: The recording band located nearest the disk outer diameter (OD) is referred to as 'Notch #1'. While
the recording band located nearest the inner diameter (ID) is called 'Notch #10'. 'Average' values are
weighted with respect to the number of LBAs per notch when the drive is formatted with 512byte blocks.
Data transfer rates Notch #1 Notch #10 Average
Buffer to/from media 12.58 9.59 12.07 MB/s (instantaneous)
Host to/from buffer up to 20.0 MB/s (synchronous) (sustained)
Data Buffer Size (bytes) 512 K (See 3.0, “Performance” on page 39 for user data capacity.)
Rotational speed (RPM) 7202.7
Average latency (milliseconds) 4.17
Track Density (TPI) 4352
Minimum Maximum
Recording density (BPI) 96,567 124,970
Areal density (Megabits/square inch) 420.3 543.9
(model numbers - > ) C4x C2x C1x
Disks 842
User Data Heads (trk/cyl) 16 8 4
Seek times (in milliseconds)
Single cylinder (Read) 0.5 0.5 0.5
(Write) 2.0 2.0 2.0
Average (weighted) (Read) 8.0 7.5 6.9
(Write) 9.5 9.0 8.5
Full stroke (Read) 16.5 15.0 14.0
(Write) 18.0 16.5 15.5
Note: Times are typical for a drive population under nominal voltages
and casting temperature of 25˚C. Weighted seeks are seeks to the cylin-
ders of random logical block addresses (LBAs).
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