I am getting massive frame drops on crysis 2, I'm using Ultra Settings, DX11 and high resolution texture packs at 1920 by 1080

It's ranging from 50 to about 30ish and sometimes even drops lower which is making it unplayable

Could anyone help me out to why it might be doing this, I can run BF3 on ultra and its fine

My Specs:

AMD Bulldozer FX-6100 3.3Ghz
Palit GTX 580 1.5Gb
4Gb DDR3 1600 RAM
WD 750GB HDD
Windows 7 Ultimate