I'm definitely thinking driver issue. I used the reference and preview 10.12 drivers, both the same. Interesting note when I installed the Hotfix 10.10e there was improvement in the overall gameplay, the fps average was a lot more stable in all games, but introduced even more microstutter. Also if you google it, there are countless complaints over the same thing with the 6xxx series. Microstutter and FPS Drops. So we have to play the waiting game.
