re: " (See what I did, there ?
) " +1 lol
RE: CPU or GPU.
(1) GPUs are simple to underclock. UNDERclock the 7850. Did the games you play get worse? You need more GPU (video card) to do better.
(2) CPUs can also be underclocked. Go into power management from control panel and set the processor speed down. (easier than frequency change in bios). Did the games you play get worse? You need more CPU (CPU/MB upgrade) to do better.
I'd guess you are close to balanced (not a bad thing) and that you will see slowing either your CPU or your 7850 (7870?) has an impact on frame rates... but it depends a lot on the game.
Final thought. If there is ONE game you play 90% of the time, find out if the web thinks that game...