Re: harddisk speed: 2.4.24 20+% faster then 2.6.3

[dth@ncc1701.cistron.net (Danny ter Haar)]

Paul  <set@pobox.com> wrote:
>By default, my hdparm numbers and my kernel build time
>benchmark were worse on all 2.6 vs. 2.4 kernels, until I tried:
>/sbin/hdparm -a 4096 /dev/hdx
>eg. (typical averages)
>2.4.21:
>Timing buffered disk reads:   80 MB in  3.07 seconds =  26.06 MB/sec
>2.6.0-test5:
>Timing buffered disk reads:   68 MB in  3.06 seconds =  22.21 MB/sec
>2.6.1: [readahead 4096]
>Timing buffered disk reads:   90 MB in  3.02 seconds =  29.82 MB/sec

Allready thought about that, tried that but no real

difference:belfish:~# uname -a
Linux babelfish 2.6.3-mm4 #3 Fri Feb 27 14:09:38 CET 2004 i686 GNU/Linux

babelfish:~# /sbin/hdparm -a 4096 /dev/hda
/dev/hda:
setting fs readahead to 4096
readahead    = 4096 (on)

babelfish:~# hdparm -t /dev/hda
Timing buffered disk reads:  110 MB in  3.02 seconds =  36.47 MB/sec

I just installed a news amd64 en few 19" servers.
But none of them showed downgrade in performance when i upped the
kernel.

Possibilities left (according to me!)

- scheduler (should i try different setup ?)
- irq problems (in combination with acpi?)
  i booted with acpi=off and retested but same results.
- driver, specific the via-onboard.

No luck so far!

Danny
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