Thank you my friend, " force-d3d11" reduced both RAM usage and Craphic Card memory usage (I have 16gb Ram anyway but GPU memory usage reduced to 1.2GB from 2GB ) but fps doesnt change. I think i was wrong, fps problem didnt have connection with GPU memory usage. Idk what to do right now lol, my GPU usage is %40-50 and CPU usage is %15-25 when i am in KSP, and getting 17-22fps ingame, with 15-20 parts (60fps without RSS/Kopernicus). Is that normal ? I mean maybe it is what Rss does? Couldt i get more fps if my GPU and CPU usages were %90-100 ?
edit : i get same FPS even if i make graphic options of the game lowest, or maximum (AAx8, maximum shader/texture etc), it doesnt change fps