----------  Original message  ----------
Subject: G5 Graphics Card
Date:    Thursday, 17. January 2013
From:    "Da'Birdman" <[email protected]>
To:      [email protected]
> Do any of you know if a NVidia GeForce 7300GT video from a MacIntel Mac Pro
> tower will work in a G5 Quad Core tower (or, for that matter, any other
> non-MacIntel tower)?  Thanking you in advance.

I know you’ve already gotten your answer, but this seems noteably to me:

Intel Mac graphics cards have an EFI based firmware on them, so they are 
compatible with the EFI based Intel macs. Otherwise the graphics card is 
identical to a Power Mac or PC version.

Power Mac graphics cards have an Open Firmware based firmware on them.

And PC graphics cards have BIOS based firmware on them, or newer cards maybe 
also have an EFI-aware firmware as well. But it’s propably different from the 
one used in Intel Macs.


IF you can find an Open Firmware based firmware for that specific card, you 
can try to flash it. If none is available there is now way. And flashing is 
not so very trivial either.


One thing is interesting though: I’ve once used a PC version of a graphics 
card in a Power Mac computer. Due to the BIOS based firmware, the computers’ 
Open Firmware was unable to initialize it and the screen stayed dark. I booted 
into Linux (because that is what I used back then) and the Linux kernel 
detected this PCIe graphics card and loaded the appropriate driver and with it 
the card was initialized. So, once the operating system took over, it all 
worked even though it was the wrong firmware on the graphics card.

On Mac OS X the graphics driver will not work though, because it has built-in 
logic to check for certain Open Firmware variables (or EFI variables, if 
you’re on Intel). In other words, it relies on Open Firmware (or EFI on Intel) 
to initialize the card and takes over from there. Mac OS X will therefor never 
work with an identical graphics card that has the wrong firmware on it.


Just to make things more complicated, I guess…

Cheers,
Andreas  aka  Mac User #330250

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