Help! With annoying fps drops/screen freeze.

I just bought Grim Dawn a few days ago and I have to say that I really love this game. So far I have only played for 8 hours and while I enjoy the gameplay, the atmosphere and the vast customisation options somethings keep bothering me and that are the annoying fps drops i get while wandering around the world of Grim Dawn. They come out of nowhere and are just there without any recognizable reason. To clarify this the drops just happen when I am wandering around, not when I fight or loot stuff. Those drops are not for a long time and are more like a screen freeze for a split second than a real frame drop but they are still annoying besides that the game runs with constant 60fps(with a CPU usage of 20-30%). I also have problems like this in Risen, PoE and Dirty Bomb. Other games run smooth. I also already tried to update my drivers, set down the graphic options,defragmented my disk, checked my PC for viruses and trojans(multiple times) and disabled ‘‘Cloud Saving’’ in Grim Dawn. It didn’t helped a bit.
Here are my Specs:
GPU:NVIDIA GeForce GTX 980 Ti (6GB)
CPU:Intel Core i5-3350 (4 CPUs) 3,30GHz (not overclocked)
8GB of Ram
Motherboard:ASRock H77 Pro4/MVP
HDD with 1TB and ~200GB of free space
I really hope that someone can help me with this problem.