Massive fps drops

[gerbil]

Yes is on by default.

I just played with video settings and I managed to make it work smoothly.
Vsynch on ( without vsynch I have strange lines on screen when moving), refresh rate 60, antialising FXAA, depth of field - medium, ssao and bloom - off, texture quality - medium, texture filter - trilinear, shadow quality - low, refraction and reflexion - off. It runs at 60 fps constantly. If I change one of this settings to a higher option, fps drops returns. I can play GTA V on high settings without fps drops on my pc.