Seagate BARRACUDA ST3500620SS, Product Manual

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Barracuda ES.2 SAS Product Manual, Rev. E 11
4.0 Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of Bar-
racuda ES.2 SAS drives.
4.1 Internal drive characteristics
ST31000640SS ST3750630SS ST3500620SS
Drive capacity 1,000 750 500 Gbytes (formatted, rounded value)
*
Read/write data heads 8 6 4
Tracks per inch 150,000 150,000 150,000 TPI
Peak bits per inch 1,090k 1,090k 1,090k BPI
Areal Density 164 164 164 Gbits/inch
2
Internal data rate 1,287 1,287 1,287 Mbits/sec max (variable with zone)
Sustained data rate 116 116 116 Mbits/sec max (variable with zone)*
Disk rotation speed 7,200 7,200 7,200 rpm
Avg rotational latency 4.16 4.16 4.16 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
See Section 9.4.1, "SAS physical interface" on page 55 and the SAS Interface Manual (part number
100293071) 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 7.4 8.5
Single track Typical 0.4 1.0
Full stroke Typical 14.3 15.4
2. Access to data = access time + latency time.
Read Write