Well, you could try one and then the orther to see if that fixes the artifacts.
Try disabling C1E first, run BF2 to see if the problem remains, if so, set PCI-express (and regular PCI bus to 33.3 if you have the option) to manual and lock it on 100 and run BF2 again. If this still doesn't fix it you could try disabling Graphic-ex and Linkboost (again: if you have those options) to see if that cures it.
GL.