Useless upgrade in most cases because when you are no gentoo/arch user you do not compile the whole day to make use of 6 cores instead of 4. If you want to play games then a faster gfx card is the way to go. Maybe rage could use 6 cores if you don't have got a nvidia (because of cuda) card if you want to improve the textures. Also you can still oc your i7-2700k if you want. So if you have got money to burn maybe get a nv gtx 670/680 instead.