Write up on flashing a Gigabyte AMD Radeon 7950

[yamstar]

try another bios

https://www.techpowerup.com/vgabios/?manufacturer=Gigabyte&model=HD+7850

download one there, patch it, flash it, test it

if you have a switch for bios on the card you can also look which version is on the other position.

 

[LightBulbFun]

AFAIK the 78xx when flashed broke with one of the more recent OS X updates (either 10.13.x or 10.14) (tho I have not personally tested this due to lack of HW)

this is because the EFI ROM uses the 79xx frame-buffer personality if someone made an EFI ROM with the 78xx frame-buffer personalities then it may work again

 

[Mad Davey]

Lightbulbfun as always a wealth of knowledge. I'd bet money this is the issue. In the meantime I did try another bios with the same exact result. How does one make an EFI rom with different frame buffers? I do not see anyone flashing these cards... That should have been a clue.

so I found this:
https://www.tonymacx86.com/threads/radeon-compatibility-guide-ati-amd-graphics-cards.171291/

It looks like the frambuffer in the chart is unknown for 7850 but I'd guess Futomaki since the 7870 is Futomaki.

 

[h9826790]

Lightbulbfun as always a wealth of knowledge. I'd bet money this is the issue. In the meantime I did try another bios with the same exact result. How does one make an EFI rom with different frame buffers? I do not see anyone flashing these cards... That should have been a clue.

so I found this:
https://www.tonymacx86.com/threads/radeon-compatibility-guide-ati-amd-graphics-cards.171291/

It looks like the frambuffer in the chart is unknown for 7850 but I'd guess Futomaki since the 7870 is Futomaki.

There is no way to change the framebuffer for the Mac EFI yet.

 

[Mad Davey]

Isn't anyone using a 7850 or 7870 that can verify it does not work with Mojave? I'm giving up...

 

[steverae]

Just like to extend my many thanks to @LightBulbFun and all the other people on this forum for helping me to flash my HD7950 card with Mac EFI firmware following the instructions on this and the NetKas forums (listed in the original post)

This could have been an expensive mistake but turned out to be a marvellous success thanks to the help and support I received from @LightBulbFun - This is what makes communities like this so special - Thank you Everyone.

 

[netsrot39]

I also wanted to say thanks to @LightBulbFun for the detailed guide. I just won an auction on eBay for a GV-R795WF3-3GD (Rev 1.0) which I intend to flash to Mac for my Mac Pro 2,1 after it has arrived. I have a question though. Can anyone tell me if the revision of the card matters? (I do have the earliest one)

Anyways, I can't wait to try it out. That card will be a great replacement for my Apple OEM ATI Radeon HD 5770 which is after all these years still a good card but it shows its age with more recent gaming titles.

 

[netsrot39]

Quick update on my previous post. I managed to successfully flash my first revision Gigabyte AMD Radeon HD 7950 to a custom Mac ROM with the netkas tool. Initially I had no success because I messed something up in the Terminal. It showed errors but I flashed it anyways (bad idea). Luckily that bad flash didn't brick anything. I tried again to create the ROM on a different Mac and it created the Mac ROM without any errors. I flashed the card again and voila! Everything is working great now. For flashing (and dumping) I used a different computer however, i.e. I didn't flash with Windows on the Mac Pro itself but with FreeDOS and ATIFlash (don't remember the version but it was from late 2012). I wanted to go the Windows and ATI Winflash route but for some reason I couldn't get into Windows with the unflashed GPU. That is why I had to rely again on a separate machine which was my old gaming PC that I've used for flashing GPUs many times before. I'm very glad that I still had that PC around because otherwise I'd still be trying to figure out how to get into Windows on my Mac Pro with the unflashed card 😅 (once it was flashed I could boot into Windows again without any problems – weird but I'm just glad it works now 🤔).

I attached a screenshot of System Profiler and the flashing process.

Thanks again to @netkas, @Fl0r!an for the script and @LightBulbFun for the instructions. BTW I also flashed the second BIOS on the card and left the first untouched.

 

[ikir]

There are few limitations of the 7950 Mac EFI

e.g.

1) No 4K 60Hz boot screen, not just nothing display or distorted, but will hang.
2) Not compatible with Windows EFI mode, will cause BOSD
3) Not compatible with Crossfire, will cause BOSD.

May be few more, but these are the most common issues.

If you need any of above, you have to boot from the NON Mac EFI (original) ROM (for flashed card), or UEFI ROM (for Sapphire HD7950 Mac Edition card). Or apply some other work around. e.g. Install windows in legacy mode.

Were all those issue fixed in other newer ROMs?

 

[h9826790]

Were all those issue fixed in other newer ROMs?

This is the problem coming from the Mac EFI. As long as you flashed the HD7950 with the one and only one widely available Mac EFI to gain the boot screen, this will happen.

There is no newer Mac EFI to fix this issue. The existing Mac EFI for all HD7000 series graphic card are comming from the same Sapphire HD7950 Mac Edition card.

 

[ikir]

This is the problem coming from the Mac EFI. As long as you flashed the HD7950 with the one and only one widely available Mac EFI to gain the boot screen, this will happen.

There is no newer Mac EFI to fix this issue. The existing Mac EFI for all HD7000 series graphic card are comming from the same Sapphire HD7950 Mac Edition card.

I've flashed my Gigabyte Radeon 7950 GV-R795WF3-3GD rev2, and I have a different experience:

1. HDMI seems to work in 4K but no boot screen
2. DVI is limited at FullHD but I think it is by design, works great and I can see Eli/OpenCore/BootSelector.
3. MiniDisplayport seems to work first time / one time but after a reboot macOS doesn't load anymore, I suppose this is the issue about 4K which hangs the machine, still HDMI 4K seems ok (but no boot screen)

I'm quite confused but still happy to see boot screen over DVI.
@netsrot39 @LightBulbFun

 

[h9826790]

I've flashed my Gigabyte Radeon 7950 GV-R795WF3-3GD rev2, and I have a different experience:

1. HDMI seems to work in 4K but no boot screen
2. DVI is limited at FullHD but I think it is by design, works great and I can see Eli/OpenCore/BootSelector.
3. MiniDisplayport seems to work first time / one time but after a reboot macOS doesn't load anymore, I suppose this is the issue about 4K which hangs the machine, still HDMI 4K seems ok (but no boot screen)

I'm quite confused but still happy to see boot screen over DVI.
@netsrot39 @LightBulbFun

That's 4K 30Hz, not 4K 60Hz via HDMI. This make the difference.

For DP, as long as you can force the monitor to DP 1.1 mode. The cMP will boot and will show boot screen. 4K 60Hz is just one of the setting can trigger this issue. But the actual problem is no DP 1.2 support for the HD7950 Mac EFI.

 

[netsrot39]

I've flashed my Gigabyte Radeon 7950 GV-R795WF3-3GD rev2, and I have a different experience:

1. HDMI seems to work in 4K but no boot screen
2. DVI is limited at FullHD but I think it is by design, works great and I can see Eli/OpenCore/BootSelector.
3. MiniDisplayport seems to work first time / one time but after a reboot macOS doesn't load anymore, I suppose this is the issue about 4K which hangs the machine, still HDMI 4K seems ok (but no boot screen)

I'm quite confused but still happy to see boot screen over DVI.
@netsrot39 @LightBulbFun

First of all it is really good that the script I created with the netkas tool for my first edition Gigabyte Radeon 7950 worked with your second revision card I haven't really noticed any limitations until now since I do not have a 4K screen and I haven't used the DVI port. I do have a WUXGA monitor attached to one DisplayPort and a WXGA+ screen as a second monitor attached to the other DisplayPort. Since I lack a 4K monitor I can't really test with one, sorry.

 

[meatwar]

Just a recent briefing on my latest upgrade from Catalina to Monterey (always using Dosdude patcher) om my cMP3.1

I have a VTX3D 7870 but was using a Club3D RoyalQueen 7850 (EFI 7950 flashed) since HSierra, Mojave and Catalina, went for a clean installation of Monterey with OCLP 0.61 and kaput no way to install or later boot after finished installation, always black screen (Signal lost). So back to the 7870.

Reporting here the model: Club3D CGAX-7856F (HD7850 2GDR5 13Series - RoyalQueen)
PCB board LF R17FA Rev. 2.0, this is TUL Corp. AMD AIB partner that owns PowerColor brand and former VTX3D.

 

[Azatos]

Hello! I am reading you using an online translator. Please help me flash xfx radeon hd 7850 so that the bootscreen appears. With a clear sequence of actions. I have MP 1.1/2.1. Only windows 11 is installed. Thank you.

 

[LightBulbFun]

Hello! I am reading you using an online translator. Please help me flash xfx radeon hd 7850 so that the bootscreen appears. With a clear sequence of actions. I have MP 1.1/2.1. Only windows 11 is installed. Thank you.

sadly as far as I understand it XFX cards of that generation can not be flashed as their base VBIOS just does not play well with things