I installed an Adaptec 2400A RAID card connect to four 250GB ATA drives last week. Fedora Core 1 detected it fine and installed fine. However I noticed slower performance in an app I normally run. I ran hdparm and got the following results. I'm using 2199 kernel.

BTW, the system also includes two S-ATA drives connected to the mobo. /boot is mounted on one of them (sdb1), swap the other. The rest is given to a software RAID partition where I mounted / (md0). The Hardware RAID partition is /dev/sda1 below where /home is mounted.


[root@localhost root]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/md0 476599832 2106076 450283812 1% /
/dev/sdb1 2063504 35312 1923372 2% /boot
/dev/sda1 961464200 156119700 756504896 18% /home
none 1033676 0 1033676 0% /dev/shm

[root@localhost root]# hdparm -tT /dev/md0

/dev/md0:
Timing buffer-cache reads: 3884 MB in 2.00 seconds = 1942.00 MB/sec
Timing buffered disk reads: 296 MB in 3.00 seconds = 98.67 MB/sec
[root@localhost root]# hdparm -tT /dev/sdb1

/dev/sdb1:
Timing buffer-cache reads: 3912 MB in 2.00 seconds = 1956.00 MB/sec
Timing buffered disk reads: 172 MB in 3.04 seconds = 56.58 MB/sec
[root@localhost root]# hdparm -tT /dev/sda1

/dev/sda1:
Timing buffer-cache reads: 3912 MB in 2.00 seconds = 1956.00 MB/sec
Timing buffered disk reads: 88 MB in 3.05 seconds = 28.85 MB/sec
[root@localhost root]#


As you can see, the HW RAID is much slower than the SW RAID and even slower than the non-RAID partition for buffered disk reads. Any ideas? Thanks.