Vista SLOW - Intel 82801FR RAID Controller Driver Problem?

I have a Dell XPS Gen 3 with a 82801FR Intel controller. I have it set up
to RAID 0 with two SATA drives. Vista Beta 2 installed fine with the latest
drivers off the Intel site, however, performance is SLOW, SLOW, SLOW.

I checked in the performance CPL and it shows the disk performance at 3.1.
It should be much higher, I think. I can tell a big difference, between
local disk operations and network operations. HD light is on CONSTANTLY. I
thought perhaps it was SuperFetch or Index working overtime, but I turned
those off and it still was constantly being accessed. I also checked to see
if any other drivers were slowing things down. It doesn't appear to be the
case, but it is possible.

I don't know what to do, but it really makes Vista hard to use. Are there
beta drivers available for Vista for this controller anywhere? If so, I
can't find them. Does anyone have any other suggestions on how to
troubleshoot?