Hello! I currently have a 2011 MacPro 6 core machine. Right now it has one of the ATI cards which is great, but not so great for OpenCL. Knowing I will have to pull out the ATI and use a card that will only work in Windows 7. What are my options from Nvidia. I need the most GPU cores I can get on one card. I realize I can't use a 590, but would a 580 work? A Mac Quadro 4000 will not have enough cores. Thanks for any help in advance.