Slow writes and reads to my raid array
 

I am getting slow writes and reads to my raid array, is this likely the raid card or the harddrives causing my slowness?

writing 512MB to disk takes up
to 150 second, it is about 3MB/sec, reading 512MB of data from the hard
drive takes 44 seconds, it is about 11MB/sec:
[root@101 tmp]# time dd if=/dev/zero of=file bs=1024 count=524288
524288+0 records in
524288+0 records out

real 2m27.399s
user 0m0.810s
sys 0m7.230s
[root@101 tmp]# time cat file > /dev/null

real 0m44.774s
user 0m0.170s
sys 0m0.770s

Any tips?

Thanks in advance.

We need more information than that. Post everything about your hardware and what RAID level. Also read http://www.linuxquestions.org/questi...ad.php?t=71791.