Contribute
Register

Radeon Compatibility Guide - ATI/AMD Graphics Cards

Joined
Jan 27, 2014
Messages
7
Motherboard
Gigabyte Z170X Gaming 7
CPU
6700K
Graphics
Dual R9 280 (non X)
Mobile Phone
iOS
Sounds like a power management issue to me, the R9 280X shouldn't need that much when idling. Currently I can't verify it, but I'm quite sure my R9 280 doesn't draw more than ~20W when idling (measured by internal PSU readings from classic Mac Pro).
Hey,

I see you're using r9 280 gpu. I'm having issues setting it up in Sierra. Did you have any issues similar? Looking for a solution because my system won't boot with the card.
 
Joined
Nov 4, 2016
Messages
113
Motherboard
GA-Z170x-Designare
CPU
Core i7-6700k
Graphics
AMD FirePro W9000 + Radeon 7970
So in my continued quest to continue beating my head against a brick wall until this black screen problem is fixed, I have a new idea to explore.

The Apple EFI apparently disables the integrated GPU (or perhaps, just the "first") when third party OS's are loaded. This is because third party OS's have no idea how to handle the switching between integrated and discrete graphics and there's no way Apple will invest effort into maintaining other OS's.

There are special functions/vars that get set when macOS loads via the EFI on macOS hardware. There are options out there in other EFI loaders (such as recent versions of rEFInd ... see SetAppleOSInfo() and apple_set_os.efi that emulate the EFI code necessary to spoof the version correctly). Clover was forked from rEFit. rEFind (the current flavor) has the set os option, but apparently this never made it into Clover.

Perhaps all we need to do is port some of this code over to Clover? Or get apple_set_os.efi to chain through before macOS boots?

The thing is I don't understand exactly how a GPU could be getting disabled on third party hardware like a Hackintosh. In theory it should only happen on a genuine Mac, correct? But it seems awfully suspicious.
 
Last edited:
Joined
Jun 9, 2013
Messages
10,960
Motherboard
GA-H77N-WIFI
CPU
Core i7-3770
Graphics
Intel HD 4000
Mac
MacBook, Mac mini
Mobile Phone
Android
Hi Fl0r!an. Ive took my 6870 apart put some new thermel pads and thermel paste on the GPU. done a fresh install of windows 7 on a old core 2 duo machine however i installed a program called GPU-Z its indicating that the GPU is at 35c and fan is at 40% but the fan seems to be on full throttle do you think i should find away to modify the BIOS and change the fan RPMs?

Update.

Ive managed to sort the FAN issue out. Ive changed the FAN speeds by modifying the BIOS. I just need a pair of active adaptors. Do you think two of these adaptor will work along with HDMI from the card that will allow me to use 3 monitors? https://www.amazon.co.uk/dp/B009YCE11E/?tag=tonymacx86-21

Untitled.jpg
 
Last edited:

Fl0r!an

Moderator
Joined
Jul 6, 2010
Messages
2,720
Motherboard
Asus Z170M-Plus
CPU
Intel i5-6600K
Graphics
AMD Radeon R9 280
Mac
MacBook Pro, Mac Pro
Mobile Phone
iOS
@LostVector: The AMD GPU doesn't get disabled by Clover/UEFI. It remains fully functional in OS X when removing the accelerator kext, so I think it's more likely that the GPU is left in a "bad"/unexpected state by the EFI, which causes the accerlerator kext to crash.
 
Joined
Nov 4, 2016
Messages
113
Motherboard
GA-Z170x-Designare
CPU
Core i7-6700k
Graphics
AMD FirePro W9000 + Radeon 7970
@LostVector: The AMD GPU doesn't get disabled by Clover/UEFI. It remains fully functional in OS X when removing the accelerator kext, so I think it's more likely that the GPU is left in a "bad"/unexpected state by the EFI, which causes the accerlerator kext to crash.
Isn't it always the "first" card that seems to go dead? I have tried many scenarios and that seems to be the common theme. Yes, removing the accelerator kext does get it to go live, but that may simply be an accidental feature of an extremely outdated legacy driver, no?

Regardless, I'm digging through the code for Clover and there's nothing setting the os name and vendor properties in the UEFI, which definitely happens on a real Mac. It's also clear that the something disables the Integrated GPU (which could easily just be coded as "the first GPU") after EFI ExitBootServices is called if the name and vendor are not set ... I've seen this mentioned in multiple linux threads.

Of course I'm not going to be certain until something actually works, but there are too many similarities to ignore. We know real Mac's somehow don't have this problem, so we know they are doing something different at boot. The fact that this is all happening in the EFI loading process and that third party OS's like linux see similar disabling of GPU's on genuine Mac hardware without the variables being set ... it's just so similar in nature.
 

Fl0r!an

Moderator
Joined
Jul 6, 2010
Messages
2,720
Motherboard
Asus Z170M-Plus
CPU
Intel i5-6600K
Graphics
AMD Radeon R9 280
Mac
MacBook Pro, Mac Pro
Mobile Phone
iOS
@LostVector: It's not necessarily the "first" card which will be dead, the bug only occurs when the AMD GPU has been init'ed by the UEFI driver, which isn't always the same.

Two examples from my system (other UEFI implementations can behave differently):

When booting with CSM disabled, the UEFI video driver will not be initialized when no display is connected to the AMD GPU during boot time, no matter if it's the primary or secondary video adapter. As a consequence the macOS drivers will work fine.

When booting with CSM enabled, firmware will always initialize the primary video adapter, regardless of any connected displays. To make a AMD GPU work in OS X, one has to configure it as secondary one.

The difference during boot phase is what we'd have to figure out to fix this issue.
 
Joined
Jan 25, 2014
Messages
2
Mac
Classic Mac
Mobile Phone
Hey guys, so I've been combing the boards for over a week. I picked up and xfx r9 280x double d (yeah I know now these are temperamental) ... I found a rom, updated the card and still getting the lockup 90% of the way through the black apple boot screen. Anyone have suggestions on a method or rom that I can try. Thanks
 
Joined
Jul 5, 2015
Messages
9
Motherboard
GA-B85M-HD3
CPU
i5
Graphics
RX580
Mac
MacBook Pro
Mobile Phone
iOS
I have a fully stable working rig with SMBIOS set as iMac 14.2 but only intel HD4600 as GPU, should i change it to a Mac Pro SMBIOS when i put the AMD r9 280x in? I have read these cards work OTB and use the built in macOS drivers but i am asking because Mac Pro have similar GPU's.
 

Stork

Admin
Staff member
Joined
Sep 21, 2010
Messages
12,775
Motherboard
ASUS ROG MAXIMUS X HERO Z370
CPU
i7-8700K
Graphics
RX 580
Mac
MacBook Pro, Mac mini, Mac Pro
Classic Mac
Power Mac, PowerBook
Mobile Phone
iOS
You can leave the SysDef at iMac14,2.
 
Top