No boot screens for Radeon RX 580???

Apple Master

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Original poster
Jan 13, 2009
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Los Angeles
I just bought a Sapphire Nitro RX 580 and now I find out that there is no boot screens???? How does Mojave support cards that do not show a boot screen?

Is there not a patch created for this problem?

This is really slack on Apple’s part. Wow.
 

casperes1996

macrumors 601
Jan 26, 2014
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There's a big difference between the operating system, and the pre-boot environment.

Once the operating system is loaded, the kext driver handles the card. Prior to that, the GPU needs to have an EFI ROM to interface with the Mac logic board. Basically no newer hardware has this (with exceptions). Some cards can be flashed by knowledgable people, but some cards need hardware modifications. I don't know if they're still in the game, but MacVidCards used to run a service where you could buy flashed cards off of him or get him to flash your cards for you. Others were also involved in creating the EFI ROMs but I forget all the involved parties.
 

Apple Master

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I’ve seen the MacVidCards site but they only sell Nvidia. I guess they would be a great resource to ask about this issue.
 

casperes1996

macrumors 601
Jan 26, 2014
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Horsens, Denmark
I’ve seen the MacVidCards site but they only sell Nvidia. I guess they would be a great resource to ask about this issue.

The essential idea behind it is the same regardless of Nvidia or AMD. MacVidCards probably never has flashed an AMD EFI ROM, but the idea is the same.

As far as I understand it there are two video systems for EFI/UEFI systems, and the Mac Pro uses a different pre-boot video system to what the card's ROM chip is set up for. Again, once the driver is loaded by the OS it's a different case entirely and the card is fully 100% supported by macOS, but just does not present itself to the EFI
 

casperes1996

macrumors 601
Jan 26, 2014
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Horsens, Denmark
So you are saying this can’t be solved by just adding some code?

It depends is probably the most accurate answer here. You should also be aware that a solution would mean the card would be able to show a boot screen on a Mac, but not any other computer. It's one or the other. Unless it has two ROM chips and a pin to switch between them.

If a modified ROM for EFI support exists, and the card's ROM chip is large enough to support it, you mean be able to flash that firmware onto the card.
If one exists and the ROM chip on the card isn't large enough to facilitate it, you'll need to swap the ROM chip on hardware.

If one does not exist you'll have to make one yourself.

None of this is to do with macOS. macOS fully supports the GPU. This is a difference between the card's firmware and the Mac Pro's EFI video systems.

Nothing is impossible though.

As it stands, I believe the latest AMD card we have flashed ROMs for, are the 280Xs.

If you're comfortable using a different boot manager, Clover and rEFInd have GOP modes (GOP is the video protocal used by the GPU whereas the Mac Pro uses UGA)
 
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eighteentee

macrumors newbie
Nov 12, 2018
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I'm interested in this too. I have a flashed cMP 4,1 to 5,1 running a stock AMD Radeon R9 280 3gb. I've read so many conflicting stories about using rEFInd and it screwing up the Mac permanently. I'm loathe to start messing trying to flash the AMD card but would like to try the rEFInd method. I can't find any info on the 4,1 or 5,1 using this method, only 3,1 tutorials. Is the rEFInd method workable on a 5,1?
 

MIKX

macrumors 65816
Dec 16, 2004
1,292
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Japan
I'm loathe to start messing trying to flash the AMD card but would like to try the rEFInd method. I can't find any info on the 4,1 or 5,1 using this method, only 3,1 tutorials. Is the rEFInd method workable on a 5,1?

It would help if we knew which BRAND of R9 280 which can be flashed with thr AMD HD 7950 ROM.

Do you have a Sapphire, Gigabyte, MSI etc. R9 280 ?
( XFX is not recommended as their cards often vary from the reference design )

if you want quick, helpful replies then go to your Macrumors member PROFILE and select " SIGNATURE ".

Type in all the important information about your cMP set up - my SIGNATURE is at the bottom of this post as an example.

============================================================

Your R9 280 CAN definitely be EFI flashed.

It is not that difficult if you first read ALL the posts of this link.

http://forum.netkas.org/index.php/topic,5619.0.html
I also felt threatened by what I thought was a very steep learning curve regarding flashing MD cards for Mac EFI but have since successfully flashed 6 different AMD GPUS.

If you want to try, PM me , I can take you through the process.
 
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