Performance Characteristics; Internal Drive Characteristics (Transparent To User); Scsi Performance Characteristics (Visible To User); Access Time - Seagate ST318451LW Product Manual

Cheetah X15 Product Manual, Rev. C
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 X15 family unless otherwise specified.
Refer to Section 9.10 and to the SCSI Interface Product Manual for additional timing details.
4.2.1

Access time [5]

Average – Typical
Single Track – Typical
Full Stroke – Typical
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]* 37.4
Max. [3] 48.9
SCSI interface data transfer rate (asynchronous):
Maximum instantaneous one byte wide
Maximum instantaneous two bytes wide
Synchronous formatted transfer rate
In low voltage differential (LVD) interface mode
ST318451
18.35
10
176,843
1,835
10,377
21,400
343
385-508
15k
2.0
Including controller overhead
(without disconnect) [1] [3]
Drive level
Read
msec
[2] 4.1
[2] 0.8
[2] 7.7
ST318451
60
30
1 to 1
MBytes/sec
MBytes/sec
ST39251
9.2 GByte (formatted, rounded off values)
6
176,843 Bytes (average, rounded off values)
1,835 Mbytes (unformatted, rounded off values)
10,377 Tracks (user accessible)
21,400 TPI
343 KBPI
385-508 Mbits/sec (variable with zone)
15k r/min
2.0 msec
Not including controller overhead
(without disconnect) [1] [3]
Drive level
Write Read
4.7 3.9
1.0 0.5
8.2 7.5
ST39251
30
15
5.0 Mbytes/sec [4]
10.0 Mbytes/sec [4]
Ultra2 SCSI
5.0 to 80 Mbytes/sec
Write
msec
4.5
0.7
8.0
Ultra160 SCSI
5.0 to 160 Mbytes/sec
9