ERROR 12 between Egpu and its Hd "Audio Device" on TB2 Imac.
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ERROR 12 between Egpu and its Hd "Audio Device" on TB2 Imac.  


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Joined: 2 months ago

Disclaimer 1: I spent one week trying to fix this build and create this discussion. I love you all for the work you do here.

Disclaimer 2: Excuse me for my english, I'm ignorant.

Setup: RX 5700 XT + Razer Core + Original Apple cable adapters needed (T3 enclosure to T2 Imac) on Imac 4K Late 2015 with iGpu Intel 6200

I followed @itsage guide on the same Mac. I copy here the steps:


  • Install Windows 10 ISO through Bootcamp Assistant [in macOS] + instal the correct OS build .295
  • Install DDU to remove all default graphics drivers and disable Windows automated driver installation [in Windows]
  • Create a 24MB FAT partition in Disk Utility and copy @goalque's automate-eGPU EFI onto it [in macOS]
  • Copy the 2015 21"  iMac  dsdt-modified.aml file to /EFI/CLOVER/ACPI/WINDOWS/dsdt.aml inside the EFI partition [in macOS] (I Do Have the Large memory in Device Manager)
  • Hold OPTION at boot to select EFI drive and hit Q to access  automate-eGPU EFI  [boot selection]
  • Install Intel iGPU drivers for the integrated graphics card then restart [in Windows]
  • Shut  iMac  down then connect eGPU to Thunderbolt port closest to Ethernet port [system OFF]
  • Boot into Windows via  automate-eGPU EFI  [boot selection]
  • Confirm a new Microsoft Basic Display Adapter in Device Manager then install Radeon drivers [in Windows]
  • Radeon software fives error 207 so IT'S NOT INSTALLED.

There is still Error 12. I was not understanding why. Now I've found the "problem":

1) When I disable the "Audio Device on High Definition Audio Bus" (this is the HD audio from the Razer Core) my Rx 5700 stops having error 12 and look in Device Manager without exclamation point.

2) This make a sense I think, because I'm not using HDMI cable and seems like it's too much for a TB3 to TB2 adapter to drive all the system ( graphics and hd sound) (??? NOT SURE ABOUT THAT)

3) At this poit, I thought: "I don't care about the HD audio from the eGPU, I just want to play Fortnite at really good fps, i will disable the HD Audio Device from egpu all the time i will boot or reboot my mac."

4)When I EXCERETE (with "disable" doesn't work) this HD Audio Device (I repeat: it's the audio from the enclosure) the Egpu stops having error 12, but if I right click on it in Device Manager-Properties it tell "No drivers Installed"- I mean, how is it possible? if no drivers are installed, I see it "Defaul Microsoft Graphic Card".

5) So I thought "this is a bug" and I thought the egpu was working, I tried to play but no Improvement on FPS. I'm still not sure if my egpu is working.

6) I tried also to install just graphic drivers from the packages and not audio drivers. Tried official drivers, tried bootcamp drivers, A lot of version. This doesn't change the final result.

7) In this situation, I also cant Install the AMD software, it says (summing up) " No drivers installed"

8) This is a circle I can't coming out from at the moment. When I try to update just the Graphic drivers after having excreted the HD audio device, the installation works and asks me to reboot. When I reboot, HD audio device is again in the device, Error 12 again, drivers installation for just the graphics seems to fail, and I am at the start poi again.


I'm searching solution for fixing completely this situation or  it's ok also to let work the graphic card disabling the Audio Device.

I will bee forever gratefull if you can help me!

Thanks a lot from Bologna, Italy.



To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.