I need to upgrade the video card in my mac pro 4,1 from the stock 120. The obvious candidates the "Apple" Ati 5770 and 5870 would obviously be significantly faster and provide full compatibility with my 27" Apple display, but seem to be be pretty grossly overpriced for the performance (the 5770 seems to be barely better than the stock card in my '11 iMac). That said I'm curious the 3rd party alternatives such as the GTX5xx and 6xx cards as well as the ATI 6870 (others?) AS LONG as they are fully compatible with my 27" Apple Display including sound (over mini-displayport? or USB?) and the built in iSight webcam -- I rely on being able to use these both for Skype and to record Screenflow tutorial. Blank boot screen I can live with if EFI is not supported. Does any one here have HANDS ON experience with the 3rd party video cards and full compatibility with a 27" Apple display? If any one can also get me pointed to a compatible 3rd party alternative cards that don't require additional power (via cable), that would be great as well. Thanks!