Seagate Cheetah 15K.7 FC, Product Manual

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Cheetah 15K.7 FC Product Manual, Rev. B 9
4.0 Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Cheetah 15K.7 FC drives.
4.1 Internal drive characteristics
ST3600057FC ST3450857FC ST3300657FC
ST3600957FC ST3450757FC ST3300557FC
Drive capacity 600 450 300 Gbytes (formatted, rounded off value)
*
Read/write data heads 8 6 4
Tracks per inch 165,000 165,000 165,000 TPI
Peak bits per inch 1,361 1,361 1,361 KBPI
Areal Density 225 225 225 Gbits/inch
2
Internal data rate 1.49 - 2.37 1.49 - 2.37 1.49 - 2.37 Gbits/sec (max)
disk rotation speed 15k 15k 15k RPM
Avg rotational latency 2.0 2.0 2.0 msec
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
4.2 Seek performance characteristics
See Section 10.5, "FC-AL physical interface" on page 63 and the Fibre Channel Interface Manual (part number
77767496) for additional timing details.
4.2.1 Access time
Not including controller overhead
2
(msec)
1
1. Typical access times are measured under nominal conditions of temperature, voltage,
and horizontal orientation as measured on a representative sample of drives.
,
Average Typical 3.4 3.9
Single track Typical 0.2 0.44
Full stroke Typical 6.6 7.4
4.2.2 Format command execution time (minutes)
When changing sector sizes, the format times shown below may need to be increased by 30 minutes.
Note.
There is approximately a 1.5 increase in time to format a SED drive versus a non-SED drive of the same capacity.
2. Access to data = access time + latency time.
Read Write
ST3600057FC ST3450857FC ST3300657FC
Maximum (with verify)
119 88 58
Maximum (without verify)
60 44 29