the m1-atx works great in my setup. see sig for specs - all running off an m1. as long as the cpu draws power from the 5 volt line you should be fine. so no high end athlons or p4's, but as mentioned a p3 or celeron based system should be fine. I read somewhere that other than the 12 volt line the m1 can handle as much as an opus 150 , you might want to verify that though.