[EFI Loader] Error 12 Fix in Boot Camp for Apple T2 Security Chip Macs (apple_set_os loader v0.5)  

@aa15032261, 

thank you for your straight and detailed manual. It was a massive help to pair my new MacBook Pro 2019 with my PowerColor Mini Pro.

Cheers

Hans

Thank you for your guide. The left-right-left method worked with my MBP 16'' 2019, latest windows version, connected to a Razer Core X Chroma. My graphic card is a RX 580.

It reminds me that unable to load bootx64_orinigal.efi to memory 

Is there a way to increase the countdown a bit?

I took a picture of the screen, as it went by too fast to really read it. If I'm understanding correctly, you're supposed to plug the eGPU in, and then hit a key (within like 3 seconds, and if you don't it loads the _original file?).

It's so fast that I can't tell if I'm getting the eGPU plugged in and hitting the key before it takes off. (Also, complicating things, is when I plug the eGPU in, my screen goes blank... but I can tell the timing has to be *super* close.) It doesn't seem to be helping me, but I'm not 100% sure I'm making it.

@kurito, how did you replace the pci.sys i have the same setup as you and I can’t seem to get my machine working with egpu with rtx3060 in do you have any links ?

Thank you for your guide. I was able to connect rx6600xt/sonnet egfx550 with MBP16 but it works only for external display 🙁 
When launching anything on the internal screen, eGPU doesn't works. I have tried removing/disabling discrete 5500m card, but then everything starts up on the integrated intel gpu. Does anyone know how to fix this problem?

I think installing the original driver for 6600xt with AMD xConnect can help me, but I cannot install it along with the software, since the installer says that it does not find the amd hardware. Drivers from bootcampdrivers is old and do not support 6600. 

@eugene_eugene, You will have to wait for @mat_hd to update the bootcampdrivers so that both dGPU and eGPU can work together with one set of Radeon drivers. Until then internal display loopback is not possible with original AMD drivers. Use the external monitor in the meantime.

I was able to get this to work with HDMI dummy plug and duplicate screen mode. But I have bad performance and maximal 1180p resolution. It remains only to wait for the Bootcamp driver. Thx for your answer!