My computer is 7 years old GTX 660 GPU. I have 16 gig of ram, but I think 8 will be fine. The total D/l size for this game when I bought it was just over 1GB. I don't know what FPS I have but I only get occasional stutter or freeze when around base.

Building a large base might be taxing. You can minimize that by not building a huge base and or not having dozens of fires lit all around. Other wise, everything is fine on my older system.