i dont like the term bottleneck. The bottleneck will vary in different situations. Some games need more cpu some more GPU. your current cpu will run nearly every game with good FPS in combination with that gfx card. if you bumped it up to 3ghz it would be a more balanced system. If you have a 1920x1080 monitor or higher, a 6870 is really what you need to run games smoothly with high detail at that resolution. a 6850 would be minimum at that res for a good gaming experience. If you have the money for a 6870 then go for it. If you can get that cpu to 3ghz then you would have a very good, balanced system. The cpu will restrict the performance a bit at lower resolutions, but you should still get better FPS than with a lower card in most situations. Tell us what res your monitor is and what games you play, your PSU make and model and we can make a more specific recommendation to your needs.