Performance Characteristics; Internal Drive Characteristics; Seek Performance Characteristics; Access Time - Seagate 15K.4 - Cheetah - Hard Drive Product Manual

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
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 Typical
Single track Typical
Full stroke Typical
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
ST3146854FC ST373454FC
146.8 73.4
8 4
471,916 471,916
18,351 18,351
50,864 50,864
85,000 85,000
628 628
685-1,142 685-1,142
15k 15k
2.0 2.0
Not including controller overhead
Read
3.5
0.2
7.4
ST336754FC
36.7 Gbytes (formatted, rounded off value)
2
471,916 Bytes (average, rounded off values)
18,351 Mbytes (unformatted, rounded off value)
50,864 Tracks (user accessible)
85,000 TPI
628 KBPI
685-1,142 Mbits/sec (variable with zone)
15k rpm
2.0 msec
1 2
,
(msec)
Write
4.0
0.4
7.9
11