If you feel up to it update your MB bios. I went from having to run it with everything on low and off to most things on high. If you don't know how, get one or our resident PC gurus to walk you through it. Also I take no responsibility for damages if something goes wrong and you end up with a giant paperweight. :bigeyes:
Most likely it is because of the Bulldozer processor. Early revisions of the microcode had an issue and for some reason it took forever for motherboard manufacturers to create updated bios' based on the new microcode. The newer ones not only fix a lot of framerate issues in games but also allow you to play games that use Valve's anti-cheat stuff. Im sure you would have serious issues if you tried to play Shogun 2 or Deus Ex: Human Revolution on your old bios too. EDIT: I just posted some modified config files for Borderlands you might want to check out in the tech forum