Ok, I took a peek back at my mobo book to be sure. And I mix 1 or 2 thingy. It's the AGPFS; to set the ratio betwwen the agp bus frequency and the cpu bus frequency. Default is 2/3 agp to cpu bus. I put it at 1:1. My cpu bus is at 100mhz now. And asus said agp bus above 66mhz exceed agp spec for agp interface and are not guaranteed to be stable. I'm not having problem right now. I'm using 13mhz dimms Maybe I could higher my fsb ?