Seagate ST3146854FC Cheetah 15K.4 FC Product Manual - Page 23

Performance characteristics

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4.0 Performance characteristics This section provides detailed information concerning performance-related characteristics and features of Cheetah 15K.4 FC drives. 4.1 Internal drive characteristics Drive capacity Read/write data heads Bytes per track Bytes per surface Tracks per surface (total) Tracks per inch Peak bits per inch Internal data rate Disc rotation speed Avg rotational latency ST3146854FC 146.8 8 471,916 18,351 50,864 85,000 628 685-1,142 15k 2.0 ST373454FC 73.4 4 471,916 18,351 50,864 85,000 628 685-1,142 15k 2.0 ST336754FC 36.7 2 471,916 18,351 50,864 85,000 628 685-1,142 15k 2.0 Gbytes (formatted, rounded off value) Bytes (average, rounded off values) Mbytes (unformatted, rounded off value) Tracks (user accessible) TPI KBPI Mbits/sec (variable with zone) rpm msec 4.2 Seek performance characteristics See Section 9.5, "FC-AL physical interface" on page 64 and the Fibre Channel Interface Manual (part number 77767496) for additional timing details. 4.2.1 Access time Average Single track Full stroke Typical Typical Typical Not including controller overhead1,2(msec) Read Write 3.5 4.0 0.2 0.4 7.4 7.9 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.4 FC Product Manual, Rev. C 11

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Cheetah 15K.4 FC Product Manual, Rev. C
11
4.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Cheetah 15K.4 FC drives.
4.1
Internal drive characteristics
ST3146854FC
ST373454FC
ST336754FC
Drive capacity
146.8
73.4
36.7
Gbytes (formatted, rounded off value)
Read/write data heads
8
4
2
Bytes per track
471,916
471,916
471,916
Bytes (average, rounded off values)
Bytes per surface
18,351
18,351
18,351
Mbytes (unformatted, rounded off value)
Tracks per surface (total)
50,864
50,864
50,864
Tracks (user accessible)
Tracks per inch
85,000
85,000
85,000
TPI
Peak bits per inch
628
628
628
KBPI
Internal data rate
685-1,142
685-1,142
685-1,142
Mbits/sec (variable with zone)
Disc rotation speed
15k
15k
15k
rpm
Avg rotational latency
2.0
2.0
2.0
msec
4.2
Seek performance characteristics
See Section 9.5, "FC-AL physical interface" on page 64 and the
Fibre Channel Interface Manual
(part number
77767496) 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
7.4
7.9