"W" wrote:

I have a Windows XP installation on a Dell Precision workstation
where the drives apparently have no cache at all in the OS.
There is extremely heavy disk access on all operations and it
doesn't feel like the OS has cached any of the disk into memory.
What are the options I need to check to help understand if
some default caching operations have been disabled for the
drive?

Drive is a RAID pair of 160GB Seagate SATA drives. Certainly
they are not speedsters, but we have other computers with the
same hardware and those perform much better.

Read caching is always enabled for all drives.

For write caching, it's disabled for USB based external drives.
To check it:
Open Device Manager and expand the "Disk drives" tree.
Double-click the harddisk and go to "Policies" tab.
Make sure the "Enable write caching on the disk" is enabled.

Also check the Event Viewer and look for warning/error events
regarding disk faults in case of faulty drive.