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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
Resolved: DVI to VGA adapter, didn't work anymore in High Sierra. Connected display via Displayport - everything works.

Hi guys,

I have a cMP 4.1, flashed to 5.1, that I ultimately want to upgrade to Mojave. But I am kind of stuck currently.
So here's what I did:

1. Acquire cMP 4.1, already flashed to 5.1 (MP51.0084.B00) - check.
2. Acquire Gigabyte Radeon HD 7950 and flash it with the modified firmware provided in this thread - check. Beautiful bootscreen, everything looks fine.
3. Make a fresh install of Sierra from USB to a new HDD - check. HD 7950 works without any issues.
4. Obtain and run the full installer for High Sierra (10.13.6) in order to upgrade firmware to MP51.0089.B00 - check. Firmware update worked just as expected.
5. Proceed with installing High Sierra 10.13.6 - check. Actually, this is where the trouble began. During the installation, the screen went black, seems like High Sierra didn't like the 7950, but the installation obviously completed successfully nevertheless (just let the updater do its thing for a while although I couldn't see any GUI).

And here's the current situation:
- Start up with only the HD 7950: Screen goes black after reaching about 3/4 of the startup progress bar, where the login screen should be.
- Start up with the HD 7950 AND the original GT 120 (with the display connected to the latter): works fine, boots into High Sierra normally, both cards show up in the system report.

Obviously I am not able to install Mojave since the installer requires all installed GPUs to be Metal capable.

So the rest of the plan looked like this:

6. Obtain full installer of Mojave using Mojave Patcher - check.
7. Install Mojave - not there yet.

I am aware that certain displays are known to cause trouble (DP 1.2 / 4K) so I used an old 19" TFT connected via DVI-VGA adapter.

So as I said in the beginning, I am kind of stuck, actually. Extensive googling didn't really turn up any real solution. Any help would be appreciated!

Edit:
The problem doesn't seem to be uncommon. See here and here (in German). So it might have something to do with the AMD graphics driver in High Sierra.

But it seems that the dosdude1 High Sierra Patcher contains an "AMD GPU Patch". Still have to figure out whether this patch can be installed on my existing HS installation or whether I have to create a USB installer and start over.
 
Last edited:

tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
Hi guys,

I have a cMP 4.1, flashed to 5.1, that I ultimately want to upgrade to Mojave. But I am kind of stuck currently.
So here's what I did:

1. Acquire cMP 4.1, already flashed to 5.1 (MP51.0084.B00) - check.
2. Acquire Gigabyte Radeon HD 7950 and flash it with the modified firmware provided in this thread - check. Beautiful bootscreen, everything looks fine.
3. Make a fresh install of Sierra from USB to a new HDD - check. HD 7950 works without any issues.
4. Obtain and run the full installer for High Sierra (10.13.6) in order to upgrade firmware to MP51.0089.B00 - check. Firmware update worked just as expected.
5. Proceed with installing High Sierra 10.13.6 - check. Actually, this is where the trouble began. During the installation, the screen went black, seems like High Sierra didn't like the 7950, but the installation obviously completed successfully nevertheless (just let the updater do its thing for a while although I couldn't see any GUI).

And here's the current situation:
- Start up with only the HD 7950: Screen goes black after reaching about 3/4 of the startup progress bar, where the login screen should be.
- Start up with the HD 7950 AND the original GT 120 (with the display connected to the latter): works fine, boots into High Sierra normally, both cards show up in the system report.

Obviously I am not able to install Mojave since the installer requires all installed GPUs to be Metal capable.

So the rest of the plan looked like this:

6. Obtain full installer of Mojave using Mojave Patcher - check.
7. Install Mojave - not there yet.

I am aware that certain displays are known to cause trouble (DP 1.2 / 4K) so I used an old 19" TFT connected via DVI-VGA adapter.

So as I said in the beginning, I am kind of stuck, actually. Extensive googling didn't really turn up any real solution. Any help would be appreciated!

Edit:
The problem doesn't seem to be uncommon. See here and here (in German). So it might have something to do with the AMD graphics driver in High Sierra.

But it seems that the dosdude1 High Sierra Patcher contains an "AMD GPU Patch". Still have to figure out whether this patch can be installed on my existing HS installation or whether I have to create a USB installer and start over.
Make a createinstallmedia usb-key for 10.13.6, do a totally clean install of 10.13.6 with a clean disk and GT120 only. Check if the HD 7950 stops working after you install it.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
Make a createinstallmedia usb-key for 10.13.6, do a totally clean install of 10.13.6 with a clean disk and GT120 only. Check if the HD 7950 stops working after you install it.

I just did a bit of investigation regarding the dosdude1 High Sierra patcher. The app package contains the "macOS Post Install" app, which has AMDRadeonX3000.kext and AMDRadeonX4000.kext in it, along with a shell script to install them both.
The Info.plist in the AMDRadeonX4000.kext contains a key for AMDTahitiGraphicsAccelerator and within that, the IOPCIMatch key contains (among others) the ID 0x679A1002. 0x1002 = AMD Vendor ID, 0x679A = HD 7900 series device ID.

So what I will try first is to extract the shell script and the kext from the package, modify the shell script in order to install just the AMDRadeonX4000.kext and run it on my existing HS installation. Then throw out the GT 120, put in the 7950, see what happens.

If this doesn't solve the issue, I will do a fresh install with a createinstallmedia key. :)
 
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
I just did a bit of investigation regarding the dosdude1 High Sierra patcher. The app package contains the "macOS Post Install" app, which has AMDRadeonX3000.kext and AMDRadeonX4000.kext in it, along with a shell script to install them both.
The Info.plist in the AMDRadeonX4000.kext contains a key for AMDTahitiGraphicsAccelerator and within that, the IOPCIMatch key contains (among others) the ID 0x679A1002. 0x1002 = AMD Vendor ID, 0x679A = HD 7900 series device ID.

So what I will try first is to extract the shell script and the kext from the package, modify the shell script in order to install just the AMDRadeonX4000.kext and run it on my existing HS installation. Then throw out the GT 120, put in the 7950, see what happens.

If this doesn't solve the issue, I will do a fresh install with a createinstallmedia key. :)
Don't use the kexts from dosdude patch, it's older Sierra ones used only for MP3,1. AMD drivers from 10.13 requires SSE4.2, Xeons used into MP3,1 don't have it.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
Don't use the kexts from dosdude patch, it's older Sierra ones used only for MP3,1. AMD drivers from 10.13 requires SSE4.2, Xeons used into MP3,1 don't have it.
Okay, thank you for pointing this out. I didn't consider the fact that the dosdude patcher is designed for other/older systems as well. I will now just create a High Sierra USB install stick and do a fresh install to another SSD. Let's see how it works out, installer is currently downloading.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
TL;DR: Didn't work.

I created a new "createinstallmedia" USB stick for HS 10.13.6 and did a fresh install on an unused 500 GB SATA SSD.
Installation with the GT120 installed worked like a charm. Took out the GT120, put in the HD 7950 - black screen where the login should be.

The moment the screen turns black, the fan speeds change significantly. I haven't yet figured out what exactly happens, but it sounds like the system fans go faster and the GPU fans go slower (or probably vice versa).

Might have to review the HD 7950 EFI flash process. But given the fact that it displays the bootscreen just fine and works perfectly in Sierra, a driver issue with the High Sierra drivers seems more plausible to me...

Any hints in which direction I should investigate?
 
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
TL;DR: Didn't work.

I created a new "createinstallmedia" USB stick for HS 10.13.6 and did a fresh install on an unused 500 GB SATA SSD.
Installation with the GT120 installed worked like a charm. Took out the GT120, put in the HD 7950 - black screen where the login should be.

The moment the screen turns black, the fan speeds change significantly. I haven't yet figured out what exactly happens, but it sounds like the system fans go faster and the GPU fans go slower (or probably vice versa).

Might have to review the HD 7950 EFI flash process. But given the fact that it displays the bootscreen just fine and works perfectly in Sierra, a driver issue with the High Sierra drivers seems more plausible to me...

Any hints in which direction I should investigate?
First thing to test is to flash the original GPU firmware back and test if you get the GPU working.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
First thing to test is to flash the original GPU firmware back and test if you get the GPU working.
Alright, thanks! I have the firmware backup on my bootcamp Win7 disk, will flash it back to the GPU instead of the modded firmware and see how it goes.

What exactly would be the expected behaviour? I assume a black screen during boot until the login screen pops up?
 
Last edited:
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
Alright, thanks! I have the firmware backup on my bootcamp Win7 disk, will flash it back to the GPU instead of the modded firmware and see how it goes.

What exactly would be the expected behaviour? I assume a black screen during boot until the login screen pops up?
Yes, black screen until the GPU driver loads.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
Yes, black screen until the GPU driver loads.
Okay, so I flashed various versions of the Gigabyte stock BIOS and both versions of the modified BIOS posted in the thread I linked in my first post.
It's always like this:
1. Stock BIOS (any version): Black screen all the way. No bootscreen, no login screen.
2. Modded BIOS (any version): Boot screen works perfectly, but black screen as soon as the GPU driver loads.
3. Modded BIOS (any version) + Boot from createinstallmedia USB stick: same as 2.

Might try a USB installer created with the dosdude1 HS patcher next and see if that helps.

Since I already did the firmware update to MP51.0089.B00 from the HS full installer, maybe I could revert to Sierra now (where the HD 7950 works nicely) and upgrade to Mojave (using the Mojave full installer) from there, skipping High Sierra?

I just wonder why High Sierra (or its GPU driver) doesn't like my completely stock 7950 that seems to work perfectly for other people.

Anything else I should try?
 
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
Okay, so I flashed various versions of the Gigabyte stock BIOS and both versions of the modified BIOS posted in the thread I linked in my first post.
It's always like this:
1. Stock BIOS (any version): Black screen all the way. No bootscreen, no login screen.
2. Modded BIOS (any version): Boot screen works perfectly, but black screen as soon as the GPU driver loads.
3. Modded BIOS (any version) + Boot from createinstallmedia USB stick: same as 2.

Might try a USB installer created with the dosdude1 HS patcher next and see if that helps.

Since I already did the firmware update to MP51.0089.B00 from the HS full installer, maybe I could revert to Sierra now (where the HD 7950 works nicely) and upgrade to Mojave (using the Mojave full installer) from there, skipping High Sierra?

I just wonder why High Sierra (or its GPU driver) doesn't like my completely stock 7950 that seems to work perfectly for other people.

Anything else I should try?
It's a real HD 7950 or is a HD 7750/7850/7870/R9-270? Upload the original bios here.
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
It's a real HD 7950 or is a HD 7750/7850/7870/R9-270? Upload the original bios here.
It is a real HD 7950. Gigabyte GV-R795WF3-3GD Rev. 2.0 to be precise.
I am currently on my mobile phone, will upload the BIOS tomorrow. But it is also available on the Gigabyte website. FX1 and FY1 are the versions that the other guy modded and uploaded here and that show the bootscreen correctly.
 
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
It is a real HD 7950. Gigabyte GV-R795WF3-3GD Rev. 2.0 to be precise.
I am currently on my mobile phone, will upload the BIOS tomorrow. But it is also available on the Gigabyte website. FX1 and FY1 are the versions that the other guy modded and uploaded here and that show the bootscreen correctly.

I downloaded the FX2 firmware from TechPowerUP, it's not what I was thinking, it's a real Tahiti card.
 
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h9826790

macrumors P6
Apr 3, 2014
15,195
7,511
Hong Kong
Alright, thanks! I have the firmware backup on my bootcamp Win7 disk, will flash it back to the GPU instead of the modded firmware and see how it goes.

What exactly would be the expected behaviour? I assume a black screen during boot until the login screen pops up?

Does your Mac has the recovery partition? (Hold command + R to boot)
 
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gex85

macrumors newbie
Original poster
Dec 6, 2018
10
1
Alright, here's the solution. As I mentioned in the first post, I was using a DVI to VGA adapter, which worked perfectly with the GT 120 in Sierra AND High Sierra. It also worked with the HD 7950 in Sierra. But with the HD 7950 and High Sierra, it would cause the black screen. I am now using the Displayport output and the EFI mod-BIOS and everything works fine. Could have tried that earlier I guess, would have saved me and you guys a lot of time.

So now I will proceed to install Mojave! :)

Thank you everyone, and tsialex in particular!!
 
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VaZ

macrumors 6502
Aug 31, 2012
254
72
It's a real HD 7950 or is a HD 7750/7850/7870/R9-270? Upload the original bios here.
I have a Radeon HD 7750 and i cannot get it working in Mojave. All i can find is Hackintosh threads saying it works with Verde.kext and Lilu and WhateverGreen but those don't work for me without Clover apparently.

Has anyone managed to get this card working for a cheap Metal gpu in Mojave!?
 
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tsialex

macrumors G3
Jun 13, 2016
8,958
9,541
I have a Radeon HD 7750 and i cannot get it working in Mojave. All i can find is Hackintosh threads saying it works with Verde.kext and Lilu and WhateverGreen but those don't work for me without Clover apparently.

Has anyone managed to get this card working for a cheap Metal gpu in Mojave!?
AFAIK, since Mojave only the Pitcairn Pro and XT variants of HD 78xx "work", GPUs with CapeVerde (HD 77xx) are not supported anymore with AMD GCN drivers.
 
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h9826790

macrumors P6
Apr 3, 2014
15,195
7,511
Hong Kong
I have a Radeon HD 7750 and i cannot get it working in Mojave. All i can find is Hackintosh threads saying it works with Verde.kext and Lilu and WhateverGreen but those don't work for me without Clover apparently.

Has anyone managed to get this card working for a cheap Metal gpu in Mojave!?

I don't have 7750, can't test it.

But those kext does NOT need Clover. They are macOS kext, not Clover plugin.
 
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VaZ

macrumors 6502
Aug 31, 2012
254
72
I don't have 7750, can't test it.

But those kext does NOT need Clover. They are macOS kext, not Clover plugin.
Oh really? Which order do you recommend i install those kexts to test?
 
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akamvs

macrumors newbie
Feb 13, 2020
4
0
Same problem with R9 280x and 7970. At Sierra all worked, but in High Sierra black screen. Use DVI, try HDMI, but can't help. At 5770 all worked. Mac Pro 5.1 2012, firmware MP51.0089.B00.
 
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MIKX

macrumors 68000
Dec 16, 2004
1,799
670
Aussie in Japan
The first thing I would do is check

(1) That the correct GPU power cables are connected.

(2) Shut down - wait for 5 minutes with the Mac Pro power cable removed then dis-connect and
after that re-connect the GPU power cables - they should audibly connect.

(3) Now cold boot tup using the THREE CONSECUTIVE " Happy Mac" chimes= Hold down these keys
( P + R + Apple Command key + Option key) until you hear the 3rd. chime.
 
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akamvs

macrumors newbie
Feb 13, 2020
4
0
Cables all ok
try SMC reset
try NVRAM reset
try flashed 7970, try R9 280X - at 10.12 all ok, at 10.13 trouble.
 
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h9826790

macrumors P6
Apr 3, 2014
15,195
7,511
Hong Kong
Cables all ok
try SMC reset
try NVRAM reset
try flashed 7970, try R9 280X - at 10.12 all ok, at 10.13 trouble.
Use the original ROM. It's known that the HD7950 Mac EFI UGA can cause display issue in recent macOS.

That HD7950 Mac EFI UGA only fully compatible to the reference 7950. For any other card, even has reference ports layout, you still have to try your luck.
 
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