Dear all I've been reading for months now to fully understand the EFI-32 / EFI-64 / PCgraphic card situation related to my Mac Pro Rev.A. EFI 32. And I am still not in a position to grab the whole picture. Still considering the best nvidia solution for my old 1st. gen Mac Pro. (already sold a working APPLE ATI 5780 for mac cause of temperatures). But have not found it. My picture so far: Many people use netkas injector or similar procedures to replace a EFI 32 card with a PC Card. most of them with success. (me - I was not able to even boot my Mac with 8800 GTX (PC) in Slot one and original ATI 7300 GT (Slot 3 - 4 PCIe Lanes). No screen at all on none of these cards - just "working" the superdrive - "rrrrrr - break - rrrrr - break ...") Many people added a PC card (GTX 285) in conjunction with an EFI-32 helper card. now my question - because I am not successfull in integrating PC Cards in my Mac Pro. Has anybody tried to mix EFI 32 and EFI 64 nvidia cards in Mac Pro Rev A?. I think of buying an MAC EDITION EFI 64 GTX 285 (EFI-64, for Slot 1) in addition to NVIDIA 7300 GT (EFI-32, for Slot 3). But I won't do if there is no road to success. So - any hint will be fine. Thank you and best regards c.