RE: UDMA

Jon Masters (mastersj@periscope-systems.freeserve.co.uk)
Sun, 19 Sep 1999 20:05:30 +0100


OK. Both disks are now using DMA. I have applied the very recent TEKRAM
Flash Upgrade (which got it working) and then applied Mr. Hedrick's IDE
patches to 2.2.12. Basically, here is the output - it's still a little
crap and I'd like to go faster. My motherboard has a UDMA33 controller,
so surely the transfer rate could be twice what it is below?

I have given 3 readings for each disk so that it isn't just a "one off":

OLDER DISK:

[root@periscope mastersj]# hdparm -tT /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.34 seconds =95.52 MB/sec
Timing buffered disk reads: 64 MB in 5.51 seconds =11.62 MB/sec
[root@periscope mastersj]# hdparm -tT /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.42 seconds =90.14 MB/sec
Timing buffered disk reads: 64 MB in 5.26 seconds =12.17 MB/sec
[root@periscope mastersj]# hdparm -tT /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.40 seconds =91.43 MB/sec
Timing buffered disk reads: 64 MB in 5.31 seconds =12.05 MB/sec

NEWER DISK:

[root@periscope mastersj]# hdparm -tT /dev/hdb

/dev/hdb:
Timing buffer-cache reads: 128 MB in 1.44 seconds =88.89 MB/sec
Timing buffered disk reads: 64 MB in 4.27 seconds =14.99 MB/sec
[root@periscope mastersj]# hdparm -tT /dev/hdb

/dev/hdb:
Timing buffer-cache reads: 128 MB in 1.47 seconds =87.07 MB/sec
Timing buffered disk reads: 64 MB in 4.32 seconds =14.81 MB/sec
[root@periscope mastersj]# hdparm -tT /dev/hdb

/dev/hdb:
Timing buffer-cache reads: 128 MB in 1.44 seconds =88.89 MB/sec
Timing buffered disk reads: 64 MB in 4.28 seconds =14.95 MB/sec

Thanx,
Your ever faithful linux follower,
Jon.

-- 
Jonathan C. Masters (jonathan@oxlug.org)  www.brookes.ac.uk/~95227860
"Upon this rock I will build my church and the gates of hell
shall not prevail against it". -- Matthew 16, 17-18

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