Occasionally when the game loads the framerate will be a little lower and some studdering. Just reload and it will be fine. Not sure why, maybe a game engine issue or something in windows but I have never seen it after reload.
You will seen building and trees spawn a few miles ahead especially if you use the drone in flight. You can turn the trees and building up to not see this but some small studdering will occur if you do with motion.
There is a mod that corrects this I just found: