> > >
> > > Not entirely, there is a fair bit more CPU overhead running an
> > > IDE bus than a proper SCSI one.
> >
> > A "fair" bit on a 500mhz+ processor is really negligible.
>
>
> Ehem, a fair bit on a 500Mhz CPU is ~ 30%. I have watched a
> *single* UDMA66 drive (with read ahead, multiblock io, 32bit mode, and
> dma transfers enabled) on a 2.2.14 + IDE + RAID patched take over 30%
> of the CPU during disk activity. The same system with a 4 x 28G RAID0
> set running would be < .1% idle during large copies. An exactly
> configured system with UltraWide SCSI instead of IDE sits ~ 95% idle
> during the same ops.
Try turning on DMA
