I have AMD Athlon II x3 455 3.3GHz it used to run perfectly with my HD 6770. Since I gave my GPU to my brother for his PC. I though of getting a 6850 or 7790/7850. I don't have plans upgrading my CPU as for now. I currently play my games on 1600x900(native resolution) or 1280x720 on most games at medium/high settings and I don't have problems with my HD 6770. So I want to push more and get a 6850 or possibly the 7790/7850. My question is, will it bottleneck? What GPU can you recommend for me? Thanks.