I've just spent the whole evening struggling to overclock the system in me sig. I can run at 400 x 8 @ 1.45 vcore, but its not orthos stable. I've tried the ram various speeds, timings voltages, single stick, dual, and all the options in the bios pertaining to voltage, speeds, settings etc. I'm really beginning to think its me psu thats bombing out. Its over three years old now and while its given sterling service (and shows all the correct voltages in the bios), I think it may be failing due to age, but I'm open to suggestions/ideas. 