RAID 0 Question

[beullar]

I am running 2 WD Raptor 36Gb drives partitioned into 3 drives in a RAID 0 mounted on an MSI 865PE NEO2 (6728) motherboard, with the ICH5/5R controller and PIV 3Mhz CPU. I recently formatted all drives and reinstalled XP SP2 but used the newer Intel Matrix Storage drivers instead of the older RAID Application accelerator drivers (V 3.53) that came with the motherboard. The RAID has worked fine since installing the Matrix drivers (V 7.1) but performance is slowing significantly over time according to online tests (PCpitstop). The previous tests using the 3.53 drivers as well as the current Matrix driver showed an average Read rate of 100-110 Mgb per second per disc. But the new Matrix driver has been gradually drifting down to 25-30 mbps rate for the 3 partitions. There is no perception of a reduction in performance but all tests indicate a slowing of read rate.

The problem is not clutter or fragementation. I use Disckeeper V9 and defrag daily. I ran the older drivers for a year with no problems but ran a stripe size of 32 kb instead of the 128 kb I use now (if that makes a difference). I have ran multiple checks on the discs and found no problems.

Any suggestions on what would cause this slow down?

Thanks
beullar

Has anyone encountered any similar problems with the newer Intel Matrix drivers?
Does anyone know if the stipe size could affect performance in this manner? Along with suggestions on what other stipe sizes have worked for people.

[Midknyte]

Yes, stripe size makes a difference.
http://www.pcguide.com/ref/hdd/perf/raid/concepts/perf_Stripe.htm