There's something wrong with the game performance. I can't run most maps at 60 FPS, especially in Defiance Bay and underground areas like sewers and dungeons. These places runs between 30 and 45 FPS and in combat I get some 1s drops below 30 FPS. Changing resolution doesn't do anything: the framerate is the same at 720p, 1080p and 4K! Also, loading times are terrible: the first one takes 1 minute and when changing maps 15-20 seconds.
The temps are low and the CPU usage doesn't go above 35% (this is probably the issue here).
This is my computer:
AMD FX-8320 3,5ghz
8 GB DDR3 1600mhz
Nvidia GTX 760 2GB GDDR5
Windows 8.1 x64