mac pro 3,1 (2008), 10.8.2 Santa has been nice and gave me Gigabyte GV-N680FW3-2GD - Graphics card. It is basically your typical NVIDIA 680 but with 3 fans (and no overclocking) - I was hoping it would be super quiet. Mountain Lion's stock drivers would appear to notice when I would plug smth on HDMI port (there would be that flicker you see when the OS tries to recognize a new display) but nothing would happen. No worries - NVIDIA's drivers ( 304.00.05f02 ) are much better. I can actually plug four(4) monitors if I wanted to. HOWEVER, there is a rather vexing detail: if the HDMI cable is plugged into ANYTHING at boot, the system hangs. Same happens when it tries to wake up from sleep. If I boot the computer and THEN plug the cable into a monitor, everything works perfectly. It would appear that the HDMI device recognition is borked. I have tried two different HDMI monitors. I have tried two different known good HDMI cables. And any combination thereof. The problem manifests even if the HDMI cable is plugged into a monitor that is physically disconnected from power. Am I the only one experiencing this? Is this a feature of the card? Or of the NVIDIA Drivers? If your HDMI behaves fine (or not) in a similar config, please let me know - it will definitely help. Thank You!