One of my friends is getting his hands on a 19-slot mobo... Funny thing is he has no idea how to set up the damn thing.
What's the latest on Windows' support for more than 8 GPUs of the same brand? Would I have to set him up a Linux distro if he wanted to run 19 GPUs on that mobo? Or is 16 doable under Win10? I wasn't recommending that mobo to him due to the major point of failure risk... but hey ho he went for it. Now I can see myself setting it up for him...

That board needs 6 x P106 Mining card, as pre-req to work.
See full rig setup by BBT here -
https://www.youtube.com/watch?v=miUoqnUqk9MHe did it with Win10 - 19 x GPUs