I have a M17x R4 with 7970M. Last week I upgraded to Windows 8.1. After the upgrade, I lost my dedicated graphics until I installed these drivers (AMD 13.151). However, now I'm seeing a very strange performance issue. I was trying to play Rift on the laptop, but it was performing even worse than it was before I reinstalled the AMD drivers. I was getting about 2 FPS on settings that were previously fine for the laptop. After some experimentation I figured out that the performance is fine when I run the game in windowed mode, but it is terrible when running full screen. I realize this is a pretty specific set of circumstances, but has anyone seen something similar, or does anyone have any suggestions on what I could try to resolve this?