if you slightly upped the cpu voltage, you could get a 15-20% oc on your cpu, more than you would get out of your video card. video card will prolly overclock about 8%, cause you dont have voltage adjustments for gfx. if you overclock the ram, it would greatly increase bandwidth, but this would take a slight ram overvolt and a fan over the ram sticks, and you can easily get 15-20% oc out of your ram. i find that ram overclocks are sometimes more beneficial than just cpu overclocks, and ive never seen a ram stick that couldnt be overclocked to the next standard frequency.
um... i know for a fact that a gpu (7850 in this case) will overclock way more than 8%, i seen people do it with a minor overvolt in ASUS GPU tweak for example. ive seen 45% overclocking... and thats stable and not on water