Disk Performance issues?

Tech-Archive recommends: Fix windows errors by optimizing your registry

I ran ExPTA to help with a problem I was having. Some users get the pop-up
that indicates that outlook is waiting for data from the exchange server.
The output from ExPTA was that I have a disk bottleneck which was what I
suspected. My problem is I don't know how to speed it up anymore? The
server specs:
Dell PowerEdge 2850
6 GB RAM (even with PAE only 4 GB accessible?)
2xXeon 3 GHz HT (4 logical Proc)
Dell PERC 4e/Di
2x36 GB U320 15K Mirror - OS, Ex Sys, Logs
4x73 GB U320 15K RAID10 - DB only

According to the report I had a peak of 241 ms latency on the DB drive.
During the monitoring I opened mailboxes that experience the waiting pop-up.
These mailboxes have folders with 5K-20K items which I understand is quite
large. I am just not sure if there is anything I can do to speed up disk
access at this point? Any suggestions?


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