Slow disk operation on DL180 G5

[Istvan Gerecs]

I installed RedHat EL 4, disk read and write seem to be very slow. Two boxes installed, hw config are the same. One is installed with software RAID, the other is without any RAID.

Here is the raid resync statistics:
[root@localhost ~]# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 hdc2[1] hda2[0]
156183808 blocks [2/2] [UU]
[>....................] resync = 3.5% (5541056/156183808) finish=1181.9min speed=2123K/sec
md0 : active raid1 hdc1[1] hda1[0]
104320 blocks [2/2] [UU]

Speed is only 2 MBytes/sec.
I checked both servers with hdparm -t, both have slow rates:
/dev/hda1:
Timing buffered disk reads: 10 MB in 3.20 seconds = 3.13 MB/sec

How can i check if drivers are correctly installed? I'm not sure they work properly.