I'm playing Assassin's Creed on an AMD Phenom II X3 720 and HD 4890. The whole game seems to run very slow and feels laggy at 1280x1024. Reducing the res or settings doesn't seem to make it much smoother. I have 2GB of DDR3 RAM. All drivers are the latest. Games like Crysis Warhead, Modern Warfare 2, etc. run smoothly when maxed out at 1280x1024. Any ideas? Looking for all the help I can get.