Re: Very low fps with very good PC.

IDK what your problems are, but here are some things to look into.
What settings are you running at regarding textures?
What kind of GTX 1060 are you using?
--The 3GB or 6GB version? Because there are differences to the graphics core itself depending on what version you get with the 3GB version being 20-30 percent weaker than the 6GB model. Lastly what resolution are you trying to play at? 

I myself prioritize framerate since the game's graphics don't scale drastically better with higher settings, and smoother gameplay is a better experience. I set my texture settings to about medium with no AA, no volumetric lighting and an FOV of 95 and I get about 100-120 fps, with large firefights dropping to about 90. 

When you see what kind of PC I have, there's no reason you shouldn't have equal if not better FPS than me on paper. In fact yours should absolutely destroy mine. 

My PC specs are: 
CPU: Core i7-950 overclocked to 3.6ghz max clock(no turbo boost and from 2009)

RAM: 12GB of DDR3
GPU: GTX 970(4gb of Vram, not overclocked)

Display: Generic Freesync 144hz monitor.