Window without frame (Subnautica)

I do not know I have one such or not Wildstar all games on the Unity suffers a window without a frame instead of a full screen mode,as I just didn't eat with her shaman still click on altar and you prigaet from window to window and not without collapsing on other engines and games,but as quadrupeds window bezruki gives much less fps than in full screen mode, can anyone take decided?Alt enter still gives a window without a frame and change razrisheniya