Performance; Reliability; Formatted Capacities; Programmable Drive Capacity - Seagate 15K.4 - Cheetah - Hard Drive Product Manual

3.3

Performance

• Programmable multi-segmentable cache buffer
• 200 Mbytes/sec maximum instantaneous data transfers per port
• 15k RPM spindle; average latency = 2.0 msec
• Command queuing of up to 128 commands
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
• Adaptive seek velocity; improved seek performance
3.4

Reliability

• 1,400,000 hour MTBF
• Increased LSI circuitry integration
• Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)
• Dithering
3.5

Formatted capacities

Standard OEM models are formatted to 512 bytes per block. The sector size is selectable at format time. Users
having the necessary equipment may modify the data block size before issuing a format command and obtain
different formatted capacities than those listed.
To provide a stable target capacity environment and at the same time provide users with flexibility if they
choose, Seagate recommends product planning in one of two modes:
1. Seagate designs specify capacity points at certain sector sizes that Seagate guarantees current and future
products will meet. We recommend customers use this capacity in their project planning, as it ensures a
stable operating point with backward and forward compatibility from generation to generation. The current
guaranteed operating points for this product are:
ST336754FC
Sector Size Decimal
512 71,687,372
514 70,512,692
520 70,197,546
522 68,914,176
524 68,766,592
528
2. Seagate drives also may be used at the maximum available capacity at a given sector size, but the excess
capacity above the guaranteed level will vary between 10K and 15K families and from generation to gener-
ation, depending on how each sector size actually formats out for zone frequencies and splits over servo
bursts. This added capacity potential may range from 0.1 to 1.3 percent above the guaranteed capacities
listed above. Using the drives in this manner gives the absolute maximum capacity potential, but the user
must determine if the extra capacity potential is useful, or whether their assurance of backward and for-
ward compatibility takes precedence.
3.5.1

Programmable drive capacity

Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select Parameter List table in the SCSI Interface Product Manual. Refer to the Parameter list block
descriptor number of blocks field. A value of zero in the number of blocks field indicates that the drive shall not
Cheetah 15K.4 FC Product Manual, Rev. C
ST373454FC
Hex Decimal
445DCCC 143,374,744
433F034 141,025,384
42F212A 140,395,092
41B8C00 139,463,602
4194B80 137,577,184
ST3146854FC
Hex Decimal
88BB998 286,749,488
867E068 282,050,768
85E4254 280,790,184
8500BB2 279,041,740
83342E0 275,154,368
Hex
11177330
10CFC0D0
10BC84A8
10A1D6CC
106685C0
9