Sorry to resurrect a dead thread, but it's Easter so why not.
I just want to say thank you to all the knowledgeable posters (norbury brook, Pete Kaine.)
I bought a Gigabyte G31M-ES2L to replace an ASUS board than burnt out on me.
I thought it was IRQ conflicts causing latency, but thanks to this thread I figured out it was all energy-saving garbage in the BIOS really doing the damage. Now there are no spikes and everything is running smoothly
I also managed to get my M-Audio 1010 onto it's own IRQ and things are running great.
Thanks again everyone.