10.3 Catalyst Driver doesn't help

Well when i got my computer which has a phenom II x4 965 and ATI 5870, 4 gb ram i was wanting to play Crysis and at first i was getting about 30-60 fps in the beginning of the game(this is when i had 10.2)but when i downloaded the 10.3 driver and i was at the part where you have to destroy the 3 or 4 AA guns for the jets to fly in i was getting 30 fps Avg. Wouldnt even reach 40 fps, is the problem the driver or is it just the part in the game which i happen to be the laggiest son of gun out there. Also on ArmA 2 i get not even 30 fps it stays in the 20s for some reason.

The framerate can vary a lot in that game so I think what you are experiencing is pretty normal, also it can dip quite a good amount in the icy areas if you have SSAO enabled.

Yup. That level is Assault which is one of the more intensive levels in the game.