Hi there, I have a recently purchased 2009 Mac pro with the original GE force GT 120 GPU. I have been playing Call of DUty and the graphics are a little lacking. I am exploring my options for an update. Seems like the 5770 or 5780 are the way to go. My questions are: Would the 5770 be a noticeable upgrade in terms of game graphics? Why is this card not supported by Apple for my machine? Is the 5780 worth the extra $200? Is either card hard to install after removing the old card? Thanks, I am sure these are pretty basic questions base don the knowledge base here, but I appreciate any feedback.