I was having issues running FNV on steam. I was able to launch the game but when I loaded a save the frame rate was extreemely low [5-6 FPS]. I have an NVIDIA GTX 1080 so this should not be happening. I tried a number of fixes via mods [NVAC, 4GB Patcher, NVAS] and multiple reinstalls but to no avail, same issue. I heard that the GOG version is supposed to be better optimized for PC so I figured I would give it a try. However, I am experiencing the same low fps when I load any save or get past the intro cutscene when starting a new game. If anyone knows how to fix this issue I would very much appreciate. I am also using Windows 10.