Resolved Flashed Mac Pro 4,1 issues with Mojave and RX 580

[CrispyDog]

Hi everyone, I am having the above issue with my Mac pro that has been flashed to 5,1, and has also received all the latest firmware patches needed to run High Sierra and Mojave.

So the issue that I have been trying to work around for a while is that the RX 580 worked fine in High Sierra, but refuses to work in Mojave at any capacity. I cant get video during the USB install with Mojave, where pretty much any other version of macOS works fine from a USB installer. To get around all these problems, I simply did what a lot of guides and posts suggested. Which was the following:

Upgrade the firmware with the High Sierra Installer and reboot
Upgrade the firmware with the Mojave installer and reboot
Make sure High Sierra is updaded to 10.13.6, and run the Mojave installer from inside High Sierra
Waited for it to install, it was at this point i noticed it wasn't installing
Installed my GT 120 and the installation finished, and it booted into Mojave (without the fancy Metal animations and transparencies and whatnot but it worked)
Put the RX 580 back in

After completing all of these steps, the system will get stuck on the progress bar (what I am seeing when both video cards are installed), somewhere between halfway and 75% depending each time.

I have fully reset the SMC and PRAM and these didn't have any major impact

If someone has some insight into this I would really appreciate the help.

 

[bookemdano]

Did you buy the 580 new? Is it the Sapphire Pulse 8GB or a different one?

What output are you using on the card and what monitor? Have you tried the other outputs on the card?

I think having both cards installed can cause additional problems/extra variables. Probably better to uninstall the GT120 for testing this.

 

[CrispyDog]

Did you buy the 580 new? Is it the Sapphire Pulse 8GB or a different one?

What output are you using on the card and what monitor? Have you tried the other outputs on the card?

I think having both cards installed can cause additional problems/extra variables. Probably better to uninstall the GT120 for testing this.

It is a new 580 and it has worked decently with a few different versions of OS X I have tried it on. Unfortunately it is not the Pulse 8GB card, its the XFX Black Edition 8GB. It's a dual BIOS card so I am half tempted to just use ATIWinFlash and give it the Pulse's hardware ID.

Currently using a pretty generic HP monitor with DVI. I can potentially connect it to my Cinema Display instead or possibly use DisplayPort with a Samsung, but I don't think it's a monitor issue.

I can try taking the GT 120 out again but if I recall the monitor just stays off indefinitely on the 580 like the OS never finished booting up. Another clue for me that it isn't finishing bootup is that I am unable to see it on my network to do screen sharing/remote control to it like it is configured to do.

 

[bookemdano]

Hmm, I'm not familiar with the XFX card. I wonder if anyone else is successfully using it. I think some XFX Tahiti cards have been problematic in the past, but I don't know about the 580. If the framebuffer is mismatched then some card outputs may not work. So that's why you should try all the outputs on the card and see if any produce an image.

 

[CrispyDog]

Hmm, I'm not familiar with the XFX card. I wonder if anyone else is successfully using it. I think some XFX Tahiti cards have been problematic in the past, but I don't know about the 580. If the framebuffer is mismatched then some card outputs may not work. So that's why you should try all the outputs on the card and see if any produce an image.

I can do that.

Additionally, lack of Remote Management visibility had to do with a subnet issue. I can remote into the Mac Pro now but all I get is a black 4:3 box with a cursor in it.
[doublepost=1540068234][/doublepost]Well I certainly feel foolish now. The last of the 3 DisplayPort connections works great. bookemdano, you were onto something with the framebuffer being wrong. What is strange to me though, is that the DVI port had always worked in the past, just not wanting to work with Mojave. And evidently it was also enough of an issue to prevent remote desktop sessions from displaying video as well. A bit odd I must say. Will have to get an adapter for the Cinema Display so it can take my displayport signal.

Thanks for the help. Sometimes its the obvious thing that you didnt try because you thought that would be too easy of a fix.

 

[crjackson2134]

Did you see if that DVI port worked properly with the GT120 removed?​

 

[CrispyDog]

Did you see if that DVI port worked properly with the GT120 removed?​

It looks to work if I plug a display into it after it has booted up. I am unsure if it will work if that cable is there during bootup. I had a non-apple setup running OS X that would do something similar. Has to do with some slight support issues in the operating system as it relates to the video initilization. I might have the "sleep issue", but I will have to replicate the problem I just came across. It did not want to wake the displays up after sitting idle for a little while.

Edit: Unable to reproduce monitor wake issue at this time, could have been a fluke. If there are any further issues I will update the thread, but I think everything should be resolved at this point. Thanks guys.