Yeah, I had pretty similar problem with stuttering, I was able to play the game for ~30minutes and then some stutters came in. I went through alot of stuff to get rid of it: drivers, memory testing, installing on other storage device, tweaking in Nvidia inspector, trying different game settings and probably something else that I cant remember right now - but with no results. Then I found a forum post somewhere where people had same problem and they turned their "Maximum processor state" under Windows power settings to 98%-95% and it worked. So I tried the same thing and it has worked flawlessly so far. No idea what this is related to, my CPU temps stay around 60-70C while playing.