I upgraded my 5750 to a 7850 and saw a huge increase in performance. I couldn't even play Grid 2 at max settings but now I can along with many other games and I'm still using my Phenom II X4 945. I only bought it though because I got it for a really good deal off of newegg and it fits perfect on my MicroATX motherboard, the 7950s and 7970s would be massive for my motherboard and case. If you have a regular case and ATX motherboard, I'd say go with a 7950 or 7970, as they have 384-bit memory compared to the 7850's 256-bit. Or if you have the patience wait for the Radeon Rx 200 series like others have just said.