CERC RAID5 performance lower than everyone else

[Adam Nielsen]

Hi all,

When researching the poor performance on the CERC SATA controller in a 
PE1800 here, I noticed that many people complain that they can't get 
speeds faster than ~40MB/sec read/write.

What I'd like to know is how on earth people are getting speeds that 
high!  We've got five 160GB disks in RAID5, and I've yet to see read or 
write speed go above 7MB/sec.

This is painfully slow, and while we've managed to crawl along for a 
while now it's really beginning to show.  Unfortunately it's still at 
least a year away before we can justify replacing the machine, so if 
anyone is able to offer any pointers as to how we can speed up the CERC 
in the meantime they'd be much appreciated!

Many thanks,
Adam.