I replace my aging GeForce 8800 gt in my Mac pro -lrb- 2008 -rrb- . it output video without any flash but do not function correctly or display video at boot . after use Netkas Romcreator with the EFI rom , and then flash the card in os x 10.7 with zue flash -lrb- 2.3 -rrb- , I be able to flash the card and it function natively in OS X. Works in both my 10.6.8 and 10.7 and of course Windows 7 . Video performance be good , card be pretty quiet . however Mac user will lose functionality of the top DVI port but the other port should work fine . its nice be able to play most game at 2560 x 1600 . quite happy with my purchase , its a good cheap upgrade and have put a little more life into my aging Mac pro .