Seagate ST336754SS Cheetah 15K.4 SAS Product Manual - Page 19

3.4 Reliability • Annualized Failure Rate (AFR) of 0.62% • LSI circuitry • Balanced low mass rotary voice coil actuator • Incorporates industry-standard Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) • 5-year warranty 3.5 Formatted capacities Standard OEM models are formatted to 512 bytes per block. The block size is selectable at format time and must be a multiple of 4 bytes. 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 block 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: Capacity (Blocks) ST3146854SS Sector Size Decimal Hex 512 286,749,488 11177330 514 282,050,768 10CFC0D0 520 280,790,184 10BC84A8 522 279,041,740 10A1D6CC 524 275,154,368 106685C0 ST373454SS Decimal 143,374,744 141,025,384 140,395,092 139,463,602 137,577,184 Hex 88BB998 867E068 85E4254 8500BB2 83342E0 ST336754SS Decimal 71,687,372 70,512,692 70,197,546 68,914,176 68,766,592 Hex 445DCCC 433F034 42F212A 41B8C00 4194B80 2. Seagate drives also may be used at the maximum available capacity at a given block size, but the excess capacity above the guaranteed level will vary between other drive families and from generation to generation, depending on how each block 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. 3.6 Programmable drive capacity Using the Mode Select command, the drive can change its capacity to something less than maximum. See the Mode Select (6) parameter list table in the SAS Interface Manual, part number 100293071. A value of zero in the Number of Blocks field indicates that the drive will not change the capacity it is currently formatted to have. A number other than zero and less than the maximum number of LBAs in the Number of Blocks field changes the total drive capacity to the value in the Number of Blocks field. A value greater than the maximum number of LBAs is rounded down to the maximum capacity. 3.7 Factory-installed accessories OEM standard drives are shipped with the Cheetah 15K.4 SAS Installation Guide (part number 100350602). Cheetah 15K.4 SAS Product Manual, Rev. B 9