You just gotta do research...
So much can go into this equations, resolution, what quality mode, vsync enabled?
You can't just expect anyone to help you with so little info.
I've already done a bunch of research and always get the same info like making all my options from quality to performance and so on. My resolution is 1920x1080 at 144hz, I use 1280x960 ingame and I never have vsync enabled. My fps is capped at 999 in csgo commands. I'm also currently on Windows 10 and have turned off that Xbox GameVR thing that were related to FPS issues.