2018 Mac Mini [8th,6C,B] + RX 5700 XT @ 32Gbps-TB3 (Razer Core X Chroma) + macOS 10.15.2 & Win10 1909 [Gibby]
For me the process to get it to work is as follows:
Replace Pci.sys file again (this seems to be required each time I have to go through the process since I don't have it fixed where I can reboot the computer and not have to do this each time. I've been leaving it on overnight.
safe mode DDU 2 clean and do not restarts and 1 clean and shut down (in the options I believe I have everything unchecked except for the remove audio bus option. I'll confirm this later.)
install AMD SDK provided with latest bootcampdrivers.com Adrenalin installer(Red)
Adrenalin installer with factory reset/restart
I cannot boot with the eGPU plugged into the Mac. It is necessary to plug the eGPU in at Adrenalin install step and disconnect it before restart, then reconnect before putting in login password to finish install.
I'm on Windows 1903 build .778. I can't seem to get the build number to change when trying to downgrade, but it seems the version and build don't really matter anyways as long as you have a compliant PCI.SYS file in place.
I'm not using Bootcamp at this time (running 10.15.4).
I seem to be unable to boot if I leave the eGPU turned on. If I turn the eGPU, let the Mac mini boot up, and then turn the eGPU on, it seems to work just fine.
Any good workaround? If it were a laptop, no problem, but with the Mini, I have to hook up an HDMI monitor, boot up the system, etc.
is it possible for someone to post the 1903 pci.sys file somewhere for download? Neither versions of 1903 are available for download anymore from https://tb.rg-adguard.net/public.php . I've spent the better part of 3 weeks trying to troubleshoot this, I even joined Windows Insider and upgraded to 2004. And nothing.