I can't wait for 2024 when a third of Steam users are holding on to a deprecated Windows 10 while Microsoft has moved on to Windows One or whatever the fuck they call it.
Someone should correct me if I'm wrong, but the Maximus VIII has an M-Key connector and the 850 Evo, (maybe Pro too), are M&B key, so I'd think you'd be alright. If you're questioning the physical size, that'll definitely be fine.