User Manual

Constellation.2 SAS Product Manual, Rev. K 14
3.2 Media description
The media used on the drive has a glass substrate coated with a thin film magnetic material, overcoated with a propri-
etary protective layer for improved durability and environmental protection.
3.3 Performance
• Programmable multi-segmentable cache buffer
• 600 MB/s maximum instantaneous data transfers.
• 7200 RPM spindle. Average latency = 4.16ms
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
• Adaptive seek velocity; improved seek performance
Note. There is no significant performance difference between Self-Encrypting Drive and standard (non-Self-
Encrypting Drive) models.
3.4 Reliability
• Annualized Failure Rate (AFR) of 0.62%
• Mean time between failures (MTBF) of 1,400,000 hours
• 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, Sea-
gate recommends product planning in one of two modes:
1. Seagate designs specify capacity points at certain block sizes that Seagate guarantees current and future prod-
ucts will meet. We recommend customers use this capacity in their project planning, as it ensures a stable operat-
ing point with backward and forward compatibility from generation to generation. The current guaranteed
operating points for this product are:
Capacity (Blocks)
Sector Size
ST91000640SS, ST91000641SS &
ST91000642SS
ST9500620SS, ST9500621SS &
ST9500622SS
Decimal Hex Decimal Hex
512 1,953,525,168 74706DB0 976,773,168 3A386030
520 1,923,076,936 729FD348 961,538,472 394FE9A8
528 1,876,331,336 6FD68B48 938,165,672 37EB45A8