I need help overclocking this card. I have heard that a lot of people can overclock the memory clock to 900 and I can't seem to do that. It will barely reach 850 and any higher causes my computer to freeze. I can get the core clock to 750 and shader to 1500. Is there any way to boost it even more??? I am hoping to get some better results for Crysis (I know this card isn't great for it but that is the best one for my system.)