OK, Time to call in the big guns. I have a MacPro 5,1 with OS X 10.6.8, 26 GB Ram, ATI Radeon HD 5870 Graphics card. I want to upgrade the video card to speed up Premier Pro, After Effects....Several times I was about to buy the Nvidia Quadro 4000 for Mac then reading the reviews scared me off. Kernel panic, crashes, only one DVI port. My Radeon is rock stable, I prefer stability to speed. Is anyone using Nvidia cards (CUDA) with a MacPro and do you have these problems? Thanks