Currently Being ModeratedApr 27, 2012 10:50 AM (in response to Ramón G Castañeda)
Flashed cards use the same built-in drivers, part of the flashing process makes them look like Apple cards.
More info to come from a big island east of Asia!
Currently Being ModeratedApr 27, 2012 3:50 PM (in response to Ramón G Castañeda)
where do mutant, flashed cards get their driver support from?
Those same drivers.
See, that's part of the "magic" of flashing; changing the codes within the ROM of the flashed card to make that card "look" like an Apple OEM. As long as the ROM coded ID is the same as an Apple OEM cousin, an ID that is included in OS X drivers, then OS X allows access to and full use of the drivers.
Knowing this, one can see why only cards that are very similar to Apple OEM, i.e. same GPU families, are the only ones that can be flashed.
You can't just change the ID of a card that has completely different architecture. There are voltages, VRAM timings, pipeline actualizations, scores of functions that are coded in the ROM but must have relevance to the architecture of the card in which the ROM resides.
OS X has drivers for many families of GPUs, but anything outside that will be unuseable, with no way to add driver support via download (like Windows).
I say "no way", but in some cases, actually hacking the drivers of OS X can allow some close 2nd and 3rd cousins to enjoy some driver support......
In your 7800 GTX cards case, there are drivers for both 7800 GT series and 4500FX series cards in OS X. The GTX has similarities to both, but usually derives support from the 4500FX drivers.
Currently Being ModeratedApr 27, 2012 5:56 PM (in response to japamac)
You can't just change the ID of a card that has completely different architecture.…
That's the part I was missing. Thank you, this explains it fully.