I recently installed 2 new 660Ti's in a SLI config and overclocked them following the guide on here. I used Crysis 2 and 3 as a guide to get a stable overclock on both games and seemed to be working great. I had the overclock set and both games had no issues. The issue I have now is that one of the games (2) only opens in windowed mode. Hitting Alt+Enter places it back in fullscreen but both the card's clock speed gets stuck at the default 915MHz, will not budge no matter what's on screen. Windowed mode, they work as they should. To play in windowed mode, the game will crash with any OC setting, stock works fine. So I have two questions, why is it that if the game opens in windowed mode, the clock speed is stuck to stock when in fullscreen? Also, does the game crashing in windowed mode a indication of an unstable overclock? I've read that SLI config's do not like windowed mode. I have no desire to play anything in windowed mode and both games work great in fullscreen until the windowed mode issue came to light. My overclock is still stable in any other game or program I throw at it. Thanks