Not sure if it's a fan failure or what. I bought this 4870 a while back pre-flashed. It worked great in my 1,1 MP and I boxed it after I got a 6870. The 4870 has been boxed for like 6 months. I got this MP 2010 Hexcore a week or two ago and just installed the 4870 to run a 3rd monitor (long story). The card showed the desktop background, external PSU running great, everything is happy. I watched TV on another video card for like an hour, and went back to play with the 4870 (working fine this whole time). I moved iTunes over to the 4870 monitor and re-sized the window... As I re-sized it, I heard noises like vibrating sounds coming from the case (presumably the card)!! I stopped moving the mouse, the noise stopped, I moved it again, the noise returned. Seriously the weirdest thing ever. About 10 seconds into this weirdness, the screen goes black and says "resolution outside of scan area" or something--basically the thing went kaput. I restarted and the screen turned on, then after booting and showing the desktop background, it overheated again. I popped open the case at that point and the card was really hot to the touch! I'm not sure but either the fan has stopped or there's a short somewhere that must have happened while the card was in storage. Is there some firmware issue with the new mac that causes the fan not to work? Does it change anything that I'm using SMC fan control (default settings)? Edit: The fan IS spinning, but not nearly as fast as the 5870 is... I wonder if I broke the fan in storage. Edit 2: I noticed the video doesn't come up until login.. that normal?