290X Low FPS in Borderlands 2

Using Catalyst 13.11 beta v9.4 drivers for the 290X(ran at stock settings).Fraps used to check the FPS

 CPU:4670K Stock clock

 GPU:290X Stock

 So here is my problem.Today i tested 3 games at 2560x1440.Crysis 2,RAGE and Borderlands 2 and in that order.

 Crysis 2 and RAGE both ran maxed in everything but AA which i set to 2x as i didn't notice the difference between that and the higher options.I get 51-60 Fps in both.

 Once Borderlands 2 got installed on steam i run it,change the resolution to 1440p,changed fps cap to unlimited and maxed everything except for ambient occlusion(turned it off as it lowers the fps quite noticeable) and PhysX on low and i saw that i only get 23-30 Fps.


Is this performance to be expected or could something be causing this?

The only thing that I could think of that would cause that problem would be the Physx. But with a 4670K and the setting on low, I can't see how that would cause such a performance hit.

Bottom of the page on here http://hardforum.com/showthread.php?p=1040367449 looks like if you turn Vsync off then the FPS shoots up for some people. It could also have something to do with the 'frame pacing' setting in AMD Catalyst.

I got no idea what happened but i tried it again today and now its in the 180-190 fps range.Strange indeed.

Thanks your help anyway.