Borderlands 2 performance issues

I just got Borderlands 2 and normally performance is awesome, but when I get into fights I lose a lot of frames in the frame rate. Oddly enough my pc runs cooler during these times than it does while I play BioShock Infinite (which runs beuatifully) so I know my pc isn't at full load. 

I'm running a FX-6300 w/ Radeon 7870. One of my friends say it may be because BL2 isn't multithreaded very well, but I'm wondering if anyone else knows anything.

All settings as high as they go, except anisotropic filtering is only at 4x

(in BSI I have all settings as high as they go as well)

Do you have v-sync on?

yeah, if that is the issue can you explain how that is affecting the performance? Thanks

have you tried setting up a profile with the free radeonpro software and tweaking?

 

Fps locking tasks have the effect of framedrop because it isn't ready for sudden heavy tasks, like loading new textures etc.

Its shouldn't be on defualt, be check the Physx settings, thats a big performance hog, hell it even slows down GTX 680's to an unexceptable fps...

^ That's the first thing I thought! Borderlands 2 is a pretty demanding game with full PhysX enabled, especially on an AMD card, since PhysX aren't native to AMD. Try turning PhysX down or off completely. If that doesn't help, there might be an issue with the drivers. So try reinstalling AMD drivers if turning PhysX down/off doesn't help.

Thanks everyone, I turned vsync and the FPS cap off and my performance improved a lot. I do have PhysX maxxed out, but noticed it only seems to affect performance a lot when there are tons of particles to animate, which tends to occur more during combat.