I didn't know that. Do you have a link to this statement?
I did a search and couldn't find it. But if I do manage it, I'll post.
And who's your source regarding who develops the firmwares? Not that I don't trust you, I just want to have a good reason for hoping.
Facts available + logic.
ATI produces the PCIe cards (can be inferred from
this, and continued for the HD4870). But this also goes back to the first question above (just not a link that spells out ATI uses EBC in these cards), as the HD3870 used EBC as does the HD4870. Assuming ATI is still doing the work (Apple didn't switch to another contractor, assuming it's possible over any IP agreements they would have with ATI), it's logical that ATI would continue to do so for whatever Mac editions they produce.
If you know whether the iMac's 4850 has EFI or EBC, I'd like to know this as well. I thought it has EBC, because its ROM has been used for flashing cards, I recall (could be wrong though). I don't remember any mention of incompatibilities with old Mac Pros.
Apple has developed their own firmware for their systems (Mini, iMacs, laptops, MP's, and XServes). Meaning the main logic board.
For PCIe cards, they have their own ROM chip on them. But in the case of the iMac, the GPU is on the main logic board. So it would seem that Apple did the firmware development for the GPU as well, and Apple uses EFI, not EBC.
It's possible they went with a separate ROM for the GPU on the iMac board, and ATI provided it in the past (not sure, as I've not had access to the innards of an iMac). But I'm accustomed to integrated graphics systems adding it to the main firmware (assuming the ROM's capacity is sufficient to hold everything).
The main firmware contains code for other components attached to it, such as SATA, Ethernet, Audio, USB, and FW.
It's AMD's interest to produce cards with EBC, as they would sell more GPUs.
Yes, but not for this reason (EBC is easier). As the cards are contracted by Apple, it's not a retail part ATI can sell off as they please (need Apple's permission to do so, and Apple sells them as upgrades through the Apple store). So any other store that sells them, would have to do so with permission from Apple (i.e. buy directly from Apple if they're willing to do a quantity purchase for less than the MSRP per unit in order to make a profit). IIRC, this did happen with the HD3870, but not sure if the HD4870 ever saw sales outside of the Apple Store.
It's Apple's interest to do EFI-64 cards in order to sell new Macs (which is more interesting for them). So it totally depends on who's doing the job indeed. But I would think that Apple didn't make the firmware for the GTX 285, which is sold by EVGA. And it wasn't Nvidia's interest to make it compatible with all Mac Pros.
nVidia has no relationship with UEFI.org at all as I understand it. AMD (parent of ATI) and Apple do (both are part of the 11 corporate member Promoter group = board of directors).
