Seagate ST3146854FC Cheetah 15K.4 FC Product Manual - Page 21

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: Sector Size 512 514 520 522 524 528 ST336754FC Decimal 71,687,372 70,512,692 70,197,546 68,914,176 68,766,592 Hex 445DCCC 433F034 42F212A 41B8C00 4194B80 ST373454FC Decimal 143,374,744 141,025,384 140,395,092 139,463,602 137,577,184 Hex 88BB998 867E068 85E4254 8500BB2 83342E0 ST3146854FC Decimal 286,749,488 282,050,768 280,790,184 279,041,740 275,154,368 Hex 11177330 10CFC0D0 10BC84A8 10A1D6CC 106685C0 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 generation, 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 forward 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 9