I am deciding what cpu to get my brother for his 600 dollar pc build. I have heard all of these have similar performance, and want to know which one to purchase. I like intel's upradability options, but AMD is very good for budget builds. He wants to play games at 1080p High - Ultra Settings. The GPU is either going to be a radeon hd 7850 or a Nvidia Geforce GTX 660. Thx in Advance