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3 performance, 4 reliability, 5 formatted capacities – Seagate Cheetah 15K.5 FC ST373455FC User Manual

Page 19: 1 programmable drive capacity

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Cheetah 15K.5 FC Product Manual, Rev. D

9

3.3

Performance

• Programmable multi-segmentable cache buffer
• 800 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

• Annualized Failure Rate (AFR) of 0.62%
• Increased LSI circuitry integration
• Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)
• Dithering
• 5-year warranty

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:

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 Commands Reference 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

Sector Size

ST3300655FC

ST3146855FC

ST373455FC

Decimal

Hex

Decimal

Hex

Decimal

Hex

512

585,937,500

22ECB25C

286,749,488

11177330

143,374,744

88BB998

520

573,653,847

22314357

280,790,184

10BC84A8

140,395,092

85E4254

524

566,007,800

21BC97F8

275,154,368

106685C0

137,577,184

83342E0

528

557,874,778

21407E5A

272,662,935

10408197

136,331,467

82040CB

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