@Outlander_04 --- I share the exact sentiment. The only thing that is really hard is the fact that you cannot just go out and test this as unlike TV's wherein you can see and inspect before you buy, the result of a build is more theoretical.
I am actually basing this article from Toms:
Here the G630 and 7970, have an average of 54 fpshttp://www.tomshardware.com/reviews/gaming-fx-pentium-apu-benchmark,3120-4.html
So I should expect like 70-80% of the frame rates if it will be a 7850? (Really hard to estimate as there are very few reviews for Graphic Cards that test on lower end hardware)