The random FPS spikes that I and many other suffer from. I monitored my whole system while running the game for 1 hour and I'm slightly confused by the results. The game just simply doesn't utilize the whole system at all apart from in dungeons, which makes no sense to me.

Out in the world while running and panning the camera my FPS would spike from 85 to 42, while still playable it's irritating to a point that I can't concentrate because my eyes are so focused on the horrible stuttering. Anyway my findings so far:

World:
CPU usage: 50%
GPU usage: as low as 63%

Dungeons:
CPU usage: spikes around the 60% mark
GPU usage: 99% ( which is what it should be )

The rig I used for testing:
CPU: Intel i5-4570 @ 3.20GHz ( 4 CPUs) Haswell
RAM: 8GB Elites
GPU: Geforce GTX 670 Power Edition OC

I thought I would find the answer if I conducted these tests,yet I'm left with more questions!