My buddy runs a film production company that's been doing pretty well, and I'm upgrading his editing suite. The new machine I have for him is a 2012 3.06GHz Mac Pro with a NVIDIA Quadro 4000 for mac in there at the moment. He needs to drive two 30" ACDs, a 23" ACD, and a 24" Samsung display. The Quadro only drives two displays. I have an ATI Radeon 4870 from an older Mac Pro that I'd like to put in. Now I've checked and it won't use too much power, but the Mac Pro itself lacks enough PCI auxiliary power ports (has two, I need three). So I'm getting a y splitter and hopefully that will work so he can drive all four screens at once. My questions are: will this be dangerous/draw too much power from the logic board, and will running these two GPUs cause instability with OS X,Premiere, and the Final Cut suite. Cheers!