I start minecraft and everything seems normal for a while. I'll be able to run around do what ever I want then after a while (a long while that is roughly an hour or more) I'll suddenly have a huge lag spike and then the screen refreshes. So I'll stop let the game render all that is around me, then start moving again and the lag spike will occur and the screen will re-render. Problem is that once it has re-rendered I will have not moved an inch, and it'll persist. Even if I exit the world and come back in it'll still occur. The only way to temporarily resolve the issue is to restart minecraft, and that'll only work for the same amount of time before the issue comes back. It has never crashed my game, but I've had it on two or three worlds now and it is incredibly frustrating to have to have this issue arise and restart minecraft only to have it occur again in the same amount of time. Sorry if there is already a bug report of this out there.