3.5ghz is about all it wants to do on the gigabyte board. Won't even post past that. On Asus P5b I can get it to post higher, but temps were runaway with stock cooler, and I didn't have a better cooler to try that was easily available. So I think it's the Gigabyte holding it back with fsb wall on that board. Funny thing is that the FSB wall is different for different cpus, ie 6320, 6550 and now 6850's I've tried. However, when I put those cpus in a vanilla Asus P5b, I can push higher fsb, but cooling is subpar, and I need to basically get some more boards to test with as the P5b is getting shipped to a friend of mine.