requests/hr per spindle

Hi!

Has anyone got any empirical data as to how many requests/hr squid can
sustain per average fast hard disk?

I'm approaching ~100K hits/hr with a pair of 9G wide 'cudas on a single
controller and while I appear to have plenty of RAM free (~80M out of 256)
things are starting to slow a little.

CPU utilization is <20%, typically, so it's not the fault of the P2/300.

If it's not ram or CPU power, then it has to be disks. I'm thinking that the
Cudas are at fault - I can't see it being the SCSI bus itself.

Anyone else vote that it's time to double my RAM (thereby reducing load on
the drives) or time to add another spindle?

-- 
 Michael 'Moose' Dinn, Twisted Pair Network Consulting Incorporated
 dinn@moose.to // 902 423 4700 (voice) // 902 423 3661 (fax)
 "Duct tape is like the force. It has a light side, a dark side, and
  holds the universe together."