SW-RAID0 Performance problems

Hi,
I've successfully set up SW-RAID0 with Kernel 2.4.3 and Raidtools 0.9. I did this to increase the performance of my HD, but nothig happens. The hdparm results:
hdparm -t /dev/md0 : 20.25 MB/sec
hdparm -t /dev/hda : 20.51 MB/sec
hdaprm -t /dev/hdc : 20.71 MB/sec

I thougt the performnace of RAID0 should near 40MB/sec.
I played with different chunk-sizes, but the result was everytime the same. The drives are both Maxtor DiamondMax VL40, 30GB, DMA on.
No other drive is attached on the bus.

Here are also some bonnie++ results:

-- RAID-0 --
-- chunk-size=16 --

Version 1.01 ------Sequential Output------ --Sequential Input- --Random-

                             -Per Chr- --Block-- -Rewrite-     -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
debian           1G     7416    99  14277   20   7498     10   6942    90 27007    20 113.0      1
                       ------Sequential Create------ --------Random Create--------
                      -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files   /sec %CP  /sec %CP    /sec %CP   /sec %CP   /sec %CP    /sec %CP
                 16   267    99  +++++ +++ 10968 100   269  99    +++++ +++  1388  99

-- chunk-size=32 --

Version 1.01 ------Sequential Output------ --Sequential Input- --Random-

                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
debian           1G    7396     99 14075    20  7469    10    6945    90   26960  20   133.7   1
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP   /sec %CP   /sec %CP   /sec %CP    /sec %CP
                 16   265 100 +++++ +++ 10695  99    267   99   +++++ +++  1447 100

-- Single HD /dev/hdc1 --

Version 1.01 ------Sequential Output------ --Sequential Input- --Random-

                           -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
debian           1G   7173   96    11055  13     5038   6     5999     78    29146  21 90.7       1
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16   272 100 +++++ +++ 10482  99   274  99 +++++ +++  1437 100

Are there known performanace problems with 2.4.3, or is it necessary to apply patches to the kernel?
Or did I something wrong??
Thank you for every hint!

Andreas

Andreas Peter *** [email protected]

...

I can't say much about this... It looks like your setup is perfectly allright,
and the performance *should* go up. Instead it looks like you get a small
performance drop from using the RAID. Most odd.

Do you have more controllers in the machine ? If so could you try to move eg. hdc to the second controller ? The only thing I can imagine being the cause of the poor performance is, if your controller somehow doesn't handle both
channels very well simultaneously. It's far fetched, but it's the only
suggestion I can think of.

Maybe Andre has comments ?

I usually get a good speedup from using RAID-0 on 2.4.3 with IDE. Both with
two disks and with six. This is with Intel PIIX4 and Promise 20262
controllers.

................................................................
:   [email protected]   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:

Am Freitag, 13. April 2001 18:01 schrieb Jakob Østergaard:

The Board ist a Gigabyte 6BXDS (BX-Chipset) and 2 Celeron 533 I think the hardware is ok.

Andreas

Andreas Peter *** [email protected]