8
Cheetah 15K.7 SAS Product Manual, Rev. A
4.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Cheetah 15K.7 drives.
4.1
Internal drive characteristics
ST3600057SS
ST3450857SS ST3300657SS
ST3600957SS
ST3450757SS ST3300557SS
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 time
See Section 10.4.1, "SAS physical interface" on page 56 and the SAS Interface Manual (part number
100293071) for additional timing details.
4.2.1
Access time
Not Including controller overhead
1
,
2
(msec)
1.
Typical access times are measured under nominal conditions of temperature, voltage, and
horizontal orientation as measured on a representative sample of drives.
2.
Access to data = access time + latency time.
Read
Write
Average
Typical
3.4
3.9
Single track
Typical
0.2
0.44
Full stroke
Typical
6.6
7.4
