thanks for those links holmer they help a little, after i made that last post i decided to test a theory i had and i changed the ram divider in bios manually to linked 5:8 which downclocked the memory to 1066 instead of the stock 1:2 divider at 1333 and ive been playing cod4 for the last 40minutes without any lockups whereas before when i was using 1:2 divider it was crashing after about 20 mins or so. perhaps it is the motherboard that is causing the problems im going to try leaving it to prime and see if it locks up.