Btw you want it to go higher ^^ 20=rubbish 60=better the higher the better.
Go to google and search CCleaner this cleans all the crap.
got read of 1,820,000 MB for me lmao >.> also Un-install any games you dont want to play if you have MW2 or any other CoD that you dont play then delete it they can take alot of MB!
Also Change your crossfire settings to medium then turn your computer off then on again log in to crossfire [using gamebooster] and make settings low then log out and in again in your computer not crossfire. it got my FPS from 27 to 89 doing all that hope i helped