Hello, I have a 2009 model Mac Pro running Mac OS 10.6.8. Currently, it has the stock Nvidia graphics card in it. If I were to install a card like an Nvidia GTX 690 while leaving my old card in at the same time, will Mac OS X ignore the incompatible card or will it not work? The reason is because I want to use the GTX 690 card with Windows 7 on my second drive for VR development. But I still want to be able to use my Mac OS X drive for my studio software. Any advice would be appreciated. Thanks so much in advance. Clarification: I don't care if Mac OS X uses the card, I just want to know if the card being in there will stop Mac OS X from working, or if it will just ignore the card and carry on as usual (providing I keep the stock graphics card in there too).