Quick and dirty writeup about "plug and play" 16" Pro + Blackmagic eGPU Pro + LG5K working in Bootcamp.
DISCLAIMER: This text is quickly parsed and edited from Discord direct messages:
Ok, so quick summary as it seems I haven't found time for proper tutorial.
Windows OS build 18362.30, anything above resulted in error 12.
Install with bootcamp assistant, install macOS support package / drivers, download DDU, restart in safe mode (shift click restart in windows menu), remove drivers and disable windows automatic driver search.
On macOS side I ran the BM eGPU update tool but that did nothing. Only when OS itself put up notification "there's update for your egpu" it fixed the TB3 windows side for 5k / TB3 connection. You can dismiss the notification or click restart instantly, I dismissed first two times and it took some time to reapper, maybe even couple of boots.
I found no info how to force update check on macOS for BMD eGPU, it just happened randomly.
Before the macOS pinged BMD update moshi cable worked (DP from egpu to USB-C to LG5K) but with only 4k res. Now I can just use one TB3 cable from eGPU to LG5K with full functionality of usb hub, camera and everything, even on Windows.
Other than that it's plug and play atm, everything works beautifully. I can just boot into whatever whenever without any trouble. Windows loading screen takes some time and can stay black, but eventually it lets you log in. Having other monitor not attached to eGPU helps, or if if you keep your Pro open I guess that works too. I run clamshell mode.
Had couple driver BSODs yesterday, but that might be not related as I run SLOBS and loads of other USB devices with sketchy drivers.
But hey, now it works and and I'm happy camper
Remember to disable windows automatic updates from registry and make several restore points and backups when you get your setup working
I have one usb c monitor connected too, R5500M seems to drive that, but that's not really an issue
dGPU still gets hot but does not affect gaming as it doesn't really matter if it downclocks itself. And it might be because I have that usb-c monitor attached.
Gaming and streaming on windows drains the battery, tho, slowly. 2h gaming 70% left. I have Caldigit TB3 dock and BMD eGPU Pro connected, and I have no idea which one charges the mbp, and I dont even know if I can avoid discharging using original apple charger. Just to note, I this might be also because I'm fully utilizing TB3 to the max. I have two Lacie 2B TB3 raid arrays chained, and one USB-C SSD chained there too. I have UAD Arrow as audio interface and it needs direct TB3 connection to power and function as well.
It's very late here (going to get some sleep now) and my time is pretty limited, but I'll try to reformat this into full quide some time soon if possible. But if you have this marginal same setup as me and never made it to work, with or without Moshi cable hope this helps.
EDIT: Driver BSODs happen only when restarting from Windows start menu. Restarting balls spin quite a long and then it hangs with driver error BSOD. Funnily enough the BSOD still shows up in LG5K, so at least the egpu is working when that happens. These didn't happen first when I got this working so I guess there's something else to blame (Loupedeck, Focusrite Scarlett (Yeah I have several audio interfaces connected), Stream deck or something. But no BSOD's / hangs while gaming EXCEPT:
Borderlands 3 in DX12 mode while streaming with SLOBS. DX12 works wonders in BL3, smooth and better framerates, but there might be memory leak or something, as it hangs and restarts drivers pretty quickly into playing+streaming. RAM usage goes thru the roof. With DX11 last night I had zero issue streaming and playing, but DX11 doesn't feel as smooth and stable otherwise.