I'm using the F4 bios now and I have the same problem as before with memory timings. I was able to use performance level 7 for a pretty good little boost but any lower locks up the system. I don't know how it works but it does. Also I'm not seeing much of a difference between 1100+mhz at 5 5 5 X and sub 1000mhz at 4 4 4 12. I heard there was an F5x bios floating around soemwhere. I'm gonna see if I can track it down and test it out.