Take a look at my topic "tweak for stuttering" as it cures most fps drops and stuttering for those on good hardware.
It is worth it to tweak the graphicsrules to get rid of the "optimizations" they've done to the LOD system (which causes the fps drops and stuttering)
My tweak has worked for many players so far so take a look and you'll be surprised how good it actually can run.
Edit: the tweak actually makes the graphics go above and beyond ultra and gets rid of pop in and stuff like that. It always displays the highest quality LOD no matter the distance from the camera and thatis what gets rid of the stutters and fps drops.