Hello,
I don't know what has changed within the game to cause this but pre-Craglorn Update the game ran flawlessly for me. Ever since the patch my GPU usage would drop to about 4% every once in a while and the game would stutter. It mostly happens when running or moving the camera.
I have tried 3 different Nvidia drivers, re-installing the game, making sure temps are normal, etc. I doubt it is from my end since as I said in the previous paragraph the game used to be flawless pre-patch.
Specs:
Mobo: Asus Maximus V Formula
CPU: Intel Core i7 3770k
Memory: 16 GB Patriot 1866 MHz
GPU: Evga GTX 780 Ti
Game is Installed on a Samsung 840 SSD
OS: Windows 8.1 Update 1