Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Barracuda</strong> <strong>18LP</strong> Product Manual, Rev. E 9<br />
4.0 Performance characteristics<br />
4.1 Internal drive characteristics (transparent to user)<br />
ST39175<br />
ST318275<br />
Drive capacity 9.1 18.2 Gbyte (formatted, rounded off values)<br />
Read/write heads 5 10<br />
Bytes/track 186 186 Kbytes (average, rounded off values)<br />
Bytes/surface 2,184 2,184 Mbytes (unformatted, rounded off values)<br />
Tracks/surface (total) 11,721 11,721 Tracks (user accessible)<br />
Tracks/inch 12,580 12,580 TPI<br />
Peak bits/inch 223 223 KBPI<br />
Internal data rate 137-240 137-240 Mbits/sec (variable with zone)<br />
Disc rotational speed 7,200 7,200 r/min ± 0.5%<br />
Average rotational latency 4.17 4.17 msec<br />
Recording code 16/17 16/17 EPR4<br />
4.2 SCSI performance characteristics (visible to user)*<br />
The values given in Section 4.2.1 apply to all models of the <strong>Barracuda</strong> <strong>18LP</strong> family unless otherwise specified.<br />
Refer to Section 9.10 and to the SCSI Interface Product Manual, part number 77738479, for additional timing<br />
details.<br />
4.2.1 Access time [8]<br />
Including controller overhead<br />
(without disconnect) [1] [4]<br />
Drive level<br />
Read Write<br />
msec<br />
Average – Typical [3] 6.9 7.7<br />
Single Track – Typical [3] 0.9 1.2<br />
Full Stroke – Typical [3] 15 16<br />
4.2.2 Format command execution time (minutes) [1]*<br />
ST39175<br />
ST318275<br />
Maximum (with verify) 20 40<br />
Maximum (no verify) 10 20<br />
4.2.3 Generalized performance characteristics<br />
Data buffer transfer rate to/from disc media (one 512-byte sector):<br />
Min. [4]* 16.2 MByte/sec<br />
Avg. [4] 25.3 MByte/sec<br />
Max. [4] 28.3 MByte/sec<br />
Data buffer transfer rate to/from disc media: (< 1 track):<br />
Min. [4] 12.2 MByte/sec divided by (interleave factor)<br />
Avg. [4] 18.8 MByte/sec divided by (interleave factor)<br />
Max. [4] 21.2 MByte/sec divided by (interleave factor)<br />
*[ ] All notes for Section 4.2 are listed at end of Section 4.2.3.