eGPU hardware (eGPU enclosure, video card, any third-party TB3 cable , any custom mods)
Installation steps (what did you do to get it all going?)
Started up Windows Bootcamp normally. Hot plugged the eGPU in one of the top ports and it was detected after a minute or so. It might have helped that the nvidia drivers were already installed for the internal (dGPU) RTX 3090.
Superposition (1080p) on external monitor: 15203
Couldn't get it to run without unplugging the monitor from the internal (dGPU) Gigabyte RTX 3090.
Not exactly the best comparison, but I get 16083 on the internal Zotac RTX 3090.
This was mainly a proof of concept to see how the 2019 Mac Pro 7,1 tower desktop would behave with eGPU's. It seems to work more or less just like the laptops. There's no iGPU, so there's that.
I also tried removing all internal GPU's from the PCIe slots to see if it would boot into Windows with an eGPU. It does boot up, but there's no video output. The Windows logo blips for a second or two, but I guess once Windows gets started it doesn't know what to do. Even trying to log in blindly wouldn't bring up video.
In theory: With minimal work, you can keep using your MPX Vega's for work in MacOS or Windows, but plug in a eGPU for gaming or even work.