So this one game, assassin's creed revelations, is lagging and I'm wondering why. I have an Intel Core i3-2120 CPU @ 3.30 GHz, 6gb of ram, 64-bit operating system, an ATI radeon HD 6850 video card, and windows 7 operating system. I went on game debate and systemrequirementslab to see if I can run it. Both sites said I can run it very well at the highest settings. I put it to the highest settings and it lags. So why does it lag?