My build is almost exactly the same apart from I am running a phenom 2 955 3.2 ghz quad. My graphics card is gigabytes 6970 2gb an I run everything on 1080p on ultra settings no problem including new titles such as Dishonoured, MW3 and borderlands 2. I get 60fp continuously. When I am recording my game to same hard drive using fraps I still get 40-50fps so yeh you will be ok. I would recommend a better case though for cooling. For example mine sucks air in the bottom at the front using 2 x 80mm fans and blows out the back at the top. And my card still hits 70 celcius. But I get no lag or random glitches even 6 hours in or more.
---------- Post added at 11:20 PM ---------- Previous post was at 11:16 PM ----------
Oh uh a 650 watt psu to high end GPU's use 250-300 watts alone CPU uses about 100 watts. See what I am getting at... It's best to be running a little bit more than the minimum