I have a Mac Pro 3,1 early 2008 that's served me very well. I used to freelance edit so I needed a powerful machine at home, but I landed a fulltime gig and so the Mac Pro is mostly used for casual computer stuff at this point. However, I'd like to upgrade the graphics card to something a little more modern since I get warnings when I do fire up FCPX and After Effects CC about the Radeon 2600 being obsolete. My upper limit would be around $500 since I don't want to dump too much money into a six year old machine. I don't need anything amazing or high end, just something that would work for those programs and drive a 27" monitor. Preferably something Mac compatible that I don't have to flash and has boot screen compatibility. Thanks!