GTA 4 jumpy graphics/gameplay

[Darkst4r]

Ok so I installed a brand new MSI 5850 today, the main reason I bought it was to play GTA 4 and ArmA II.

ArmA II looks amazing but GTA 4 is so jumpy that it is virtually unplayable. Every other second the screen freezes for a moment and then continues.

I put the settings to auto detect and the problem persists, tried lowering the settings, same thing.

I'm using an AMD Phenom II 955 and 4gb OCZ Platinum RAM so I dont think this should be happening.

Any ideas ?

 

[Darkst4r]

I tried the benchmarking tool and it looked fine, averaging 50fps, my gfx temps are good too.

 

[Darkst4r]

Yeah, got the latest catalyst version. I cant believe a 5850/955 combo cant get a playable performance even at very low settings, something must be wrong