MP 1,1-5,1 RX 580 and 5770 in 2010 Mac Pro (5,1)?

[Macschrauber]

Hmm. Thought it was probably a big ask.
Oh well, I guess I can still swap back in the original ATI card when I want to.
Thanks anyway

If the RX580 gives you the OpenCore (LegacyPatcher) menu, without the (optional) preload GOP option:

You can add EnableGop to the Mac firmware, what gives you the classic Apple boot screen / boot picker.

EnableGop: Pre-OpenCore GOP support for EFI-era iMacs and Mac Pros

You wait ten years for a driver to enable pre-boot graphics on unsupported GPUs in EFI era Macs, and then two come along at once... This post is to announce a firmware driver to enable the native Apple boot picker and early macOS boot progress bar (plus other parts of the firmware UI: target...

forums.macrumors.com

 

[Manteur]

If the RX580 gives you the OpenCore (LegacyPatcher) menu, without the (optional) preload GOP option:

It didn't, but I successfully re-flashed it with the correct VBIOS from TechPowerUp and now it does, so I'm pleased with that.

You can add EnableGop to the Mac firmware, what gives you the classic Apple boot screen / boot picker.

I've been considering this very carefully. I would very much like to have the classic boot screen, but every time I hear the "this can brick your machine" warning, I hesitate. However I'm intrigued to hear you recommend it.

(It still doesn't get round the fact that there are no RX580 Windows XP drivers suitable for retro gaming, but that's a fairly minor consideration).

Idle curiosity, but what happens if you have successfully installed EnableGOP in the Mac firmware, but then reinstall a GPU that provides the boot screen anyway?

On this subject, I gather one can alternatively create a custom VBIOS containing EnableGOP and flash this into the GPU, but this seems to be by far the less popular option. Why is that?

 

[Manteur]

Macschrauber, I'm up to page 7 (of 45) on the link in this forum you included. I'll get there.