FPS on PC

I really like this game and I would love to play it more, but everytime a see a video of some silky smooth PS4 gameplay it kills me inside. I have a 4gb 960m and I can play almost all games at high settings in 1080p, why do I get like 20 fps average in NMS? Games like Dying Light and the Witcher 3 run and look amazing at high settings, but NMS runs like a dog with 1 leg and the graphics are nothing special. Am I the only one still stuck with this shitty fps? If I try reinstalling will I lose my save?