Weird Vulkan issue with 2016 15" MBP and Radeon RX 580
So I’m using a Sonnet Breakaway Box developer kit with the included Radeon RX 580 under Boot Camp on my 2016 15″ MBP with a Radeon Pro 460. For the most part, setup was really easy and worked fantastically! There’s just one extremely strange issue I’m having, and it seems to affect any software based on Vulkan.
Basically, Vulkan software works flawlessly windowed, and runs as well as you’d want it to. However, if I try to take any Vulkan game full-screen, I either get a totally black screen, or I get a still image from the game that can’t be interacted with. I also can’t alt-tab or use a mouse cursor – I have to ctrl+alt+delete to get to a task manager. When I open task manager, I can see Vulkan apps in the background running just fine. It’s only when I switch back to them and they take full-screen focus they freeze.
This only happens with my external GPU. If I play Vulkan stuff on my built-in RP460, there’s no problem. I have to think there’s some eGPU display fuckery going on that’s messing with Vulkan. Does anyone have any ideas on how this could be fixed, or where to even start?
For anyone wondering, I found one specific setup that worked. It’s not ideal or what I want, but hey, I can play Vulkan stuff this way.
Basically: I had to use apple_set_os.efi and integrated.bat to enable the iGPU. I had been keeping the dGPU before, which worked fine for everything but Vulkan stuff (and made it easier to just switch between using the eGPU and not). Then, as long as I have both my laptop display AND my external monitor up, I can play Vulkan stuff accelerated by the eGPU on my external monitor. However, if I close my laptop lid or even decide just to use the external display in Windows, then this problem comes back.
Based on this, if anyone can think of a way I can clamshell mode my laptop and have Vulkan stuff work, I would appreciate it.