Seagate ST3300457FC Cheetah 15K.5 SAS Product Manual - Page 17

Performance characteristics

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4.0 Performance characteristics This section provides detailed information concerning performance-related characteristics and features of Cheetah drives. 4.1 Internal drive characteristics Drive capacity Read/write data heads Tracks per surface (total) Tracks per inch Peak bits per inch Areal Density Internal data rate Disc rotation speed Avg rotational latency ST3300655SS 300.0 8 74,340 125,000 890 110 960 to 1607 15k 2.0 ST3146855SS ST373455SS 146.8 73.4 4 2 74,340 74,340 125,000 125,000 890 890 110 110 960 to 1607 960 to 1607 15k 15k 2.0 2.0 Gbytes (formatted, rounded off value)*,** Tracks (user accessible) TPI KBPI Gbits/inch2 Mbits/sec (variable with zone) RPM msec *One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting. **Rounded off value. 4.2 Seek time See Section 9.4.1, "SAS physical interface" on page 57 and the SAS Interface Manual (part number 100293071) for additional timing details. 4.2.1 Access time Not Including controller overhead1, 2 (msec) Read Write Average Typical 3.5 4.0 Single track Typical 0.2 0.4 Full stroke Typical 6.8 7.5 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. Cheetah 15K.5 SAS Product Manual, Rev. E 11

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Cheetah 15K.5 SAS Product Manual, Rev. E
11
4.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Cheetah drives.
4.1
Internal drive characteristics
ST3300655SS
ST3146855SS ST373455SS
Drive capacity
300.0
146.8
73.4
Gbytes (formatted, rounded off value)
*,**
Read/write data heads
8
4
2
Tracks per surface (total)
74,340
74,340
74,340
Tracks (user accessible)
Tracks per inch
125,000
125,000
125,000
TPI
Peak bits per inch
890
890
890
KBPI
Areal Density
110
110
110
Gbits/inch
2
Internal data rate
960 to 1607
960 to 1607
960 to 1607
Mbits/sec (variable with zone)
Disc 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.
**Rounded off value.
4.2
Seek time
See Section 9.4.1, "SAS physical interface" on page 57 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
3.5
4.0
Single track
Typical
0.2
0.4
Full stroke
Typical
6.8
7.5