I'm sorry for the naive question here. I see the FAQ about Nvidia cards, but I'm not sure I quite understand this. What exactly is the difference between this card (Radeon HD 7950) and this one (Radeon HD 7950, "Mac Edition")? If I tried to use the non Mac edition in my 5.1 Mac Pro (mid2010) would it not function at all? Is it really $135 extra just to work with OS X vs. Windows? Thanks.