I have a new Dell Dimension 9200 (actually two of them) and am having a
problem with hard drive stutter.

It happens on both machines.

They are E6600 Core 2 Duo, with integrated Intel raid controllers (ICH8).
They have 250Gb WD SATA II hard drives. XP Pro.

I tried recording TV last night and it was a disaster. Useless files.

So I ran HDTune. Every few seconds, the throughput of the hard drive drops
to almost zero.

If I install a second drive, either SATA or IDE with a controller card, the
second drive is fine, but the boot drive stutters.

Dell is clueless.

I tried a different drive (Seagate 300Gb). I tried a fresh XP Pro install
(thinking it was the Dell crap).

I've tried everything!

Any thoughts or suggestions?