Adaptec 2400A Performance

[Rishi Chopra]

I've run some imperical tests on the Adaptec 2400A raid controller 
(results and setup can be seen here):

http://www.ocf.berkeley.edu/~rchopra/RaidResults.html

I was rather disappointed with the results.  Can anyone suggest what 
might be causing such slow disk speeds, or whether these speeds are out 
of the ordinary for a 4-disk FreeBSD RAID5 installation?  I have done 
nothing to configure the card aside from striping the array in BIOS; 
FreeBSD seems to automatically detect the disks.

I once ran a 2-disk RAID-0 installation on Win2k which was 6-7 times 
faster on sequential read/write tests (60-70MB/sec), hence my dismay.

-- 
Rishi Chopra
http://www.ocf.berkeley.edu/~rchopra