Performance Characteristics; Internal Drive Characteristics (Transparent To User); Scsi Performance Characteristics (Visible To User); Access Time - Seagate ST318404LW Product Manual

Cheetah 18XL Product Manual, Rev. A
4.0

Performance characteristics

4.1

Internal drive characteristics (transparent to user)

Drive capacity
Read/write heads
Bytes/track
Bytes/surface
Tracks/surface (total)
Tracks/inch
Peak bits/inch
Internal data rate
Disc rotational speed
Average rotational latency
4.2

SCSI performance characteristics (visible to user)

The values given in Section 4.2.1 apply to all models of the Cheetah 18XL family unless otherwise specified.
Refer to Section 9.10 and to the SCSI Interface Product Manual, part number 75789509, for additional timing
details.
4.2.1

Access time [5]

Average – Typical [2]
Single Track – Typical [2]
Full Stroke – Typical [2]
4.2.2

Format command execution time (minutes) [1]

Maximum (with verify)
Maximum (no verify)
4.2.3

Generalized performance characteristics

Minimum sector interleave
Data buffer transfer rate to/from disc media (one 512-byte sector):
Min. [3]* 26
Avg. [3] 33
Max. [3] 40
SCSI interface data transfer rate (asynchronous):
Maximum instantaneous one byte wide
Maximum instantaneous two bytes wide
Synchronous formatted transfer rate
In single-ended (SE) interface mode
In low voltage differential (LVD) interface mode
ST318404 ST39204
18.352 9.176
6 3
203,008 203,008
3,058 3,058
14,384 14,384
18,145 18,145
339 339
285-424 285-424
10,033 10,033
2.99 2.99
Including controller overhead
(without disconnect) [1] [3]
Drive level
Read Write
msec
5.4 6.0
0.8 1.1
10.2 11.2
ST318404
25
12
1 to 1
MByte/sec
MByte/sec
MByte/sec
GByte (formatted, rounded off values)
Bytes (average, rounded off values)
Mbytes (unformatted, rounded off values)
Tracks (user accessible)
TPI
KBPI
Mbits/sec (variable with zone)
r/min (+0.5%)
msec
Not including controller overhead
(without disconnect) [1] [3]
Drive level
Read Write
msec
5.2 5.8
0.6 0.9
10.0 11.0
ST39204
13
6
5.0 Mbytes/sec [4]
10.0 Mbytes/sec [4]
Ultra2 SCSI
5.0 to 40 Mbytes/sec
5.0 to 80 Mbytes/sec
9
Ultra160 SCSI
5.0 to 80 Mbytes/sec
5.0 to 160 Mbytes/sec