Hi everybody, I'm feeling so mentally tired that i can't use a XFX R9 280X in a MacPro 3.1 with Yosemite. After all tries, i'm running Windows 8 on the MacPro (and it still seeing the card as a Radeon HD 7900 Series). I'm desperate. Please, help me to get it working on Yosemite. The MacPro can see the card as a "monitor" but don't know what it is. It will boot on a second card (or a MSI GT 610 without boot screen or on the stock XT 2600) but no way to use the XFX. Please, help me with that.