Story behind the question: My ATI Radeon HD 5400 graphics card might not be the best but it's good enough to run most of nowdays games, while my Pentium 4 3.2 GHz CPU is always under the minimum requirements, but some games still run smoothly because of the graphics card I guess, like Assassins Creed Revelations, which can run on Max graphics setting with no lag at all, some other games like Need for speed hot pursuit's fps drop to ~5 or something, so I'm really curious to know which part affects the performance more, and how every part works when it comes to gaming.