Hello, I've recently installed a GTX 680 Mac Edition in my 2009 Mac Pro, substituting my old HD 4870. First thing I noticed is that when I press the power button the computer stays dead silent for 5 seconds before chiming, whereas with my old GPU I could hear all the fans spinning like crazy. Is that normal? The strangest thing though is that when I had just installed it all OS animations where extremely jerky, like they were running at 3 fps. I tried rebooting a couple of times, checking if everything was properly connected, installing latest NVIDIA web drivers, resetting PRAM, but nothing changed. Then I tried running a benchmark (Geeks3D GpuTest) and after that all of a sudden everything started running smoothly. Anyone has any idea of how is that possible? Running the FurMark benchmark I got 47 fps, whereas another user with the exact same settings (1920x1200 windowed, antialiasing off) and drivers got 56 fps. Is that because he had a more powerful CPU? What results are you guys getting? Thanks for the help!