OK just recently got a macpro 1,1. Upgraded the firmware to 2,1 have a set of x5365 currently in the mail. 32gb of ram as well as a ssd that I will be installing. Now I'm trying to verify that my final piece will fit the puzzle. Boot screen is not an issue since I will still have my 7300 gt for boot. I can not verify if this card is compatible I have found that the pny quadro 4000 will work but not the k series does anyone have any input. Currently running 10.7.5 lion I do know I will need to upgrade to at least mountain lion to get the driver compatibility. Any help would be appreciated thank you.