You need to understand, CPU's with multiple cores are for running multiple things simultaneously without exerting any lag on your other programs running, this is good for rendering or ripping/burning media but in gaming it doesnt contribute that much and yes I do know that people have been saying it runs best on Quad Core but they've probably forgotten that their Graphics Card is doing most of the work, hell you could run Battlefield 3 on an Intel/AMD Dual Core processor and still get sick graphics just because you have a good graphics card, graphics card is the most important component in gaming because it takes a huge amount of strain off the CPU and it renders better thus making you games look sick, you OS (Operating System) also contributes to this because it runs apps in the background, to squeeze the utmost out of your PC I suggest using Gamebooster, it turns off all apps that are not needed and it basically speeds up your PC and it can be undone with a push of a button. Also if you are a person who goes the extra mile at squeezing the best performance out of your PC then you should run Dual Boot with your Windows 7 and Windows XP, Windows XP uses less resources and doesnt contribute to ingame lag.