I've got a 560ti. For the past month or so sometimes it cannot wake up once it goes to sleep. I left it alone for about 1/2hr today, it went to sleep and now both of my screens no longer see any input from any port. Its not a PSU issue I have a 850w corsaire power supply. Way overkill for my board. The ventilation in my PC is great none of my temps surpass 50. I've tested with many cables, and I doubt the PSU is dead because all the fans spin and I can feel the hard drive spinning up.