Hi Lars,
I was told that they have XP running on a Ryzen 5 system as the only OS but that they had to patch a couple of drivers to do so. I haven't seen it and the youngsters that did it did it for fun just to say they had.
The CoreInfo dump was sent to me by the guy I built a Ryzen system for so I hope it is the correct one - I have two Ryzen systems here but they are running Linux until I can, hopefully, get OS/2 running on them and I can't find a Coreinfo program for Linux or I would have done it myself. I will be seeing the guy over the weekend and will make sure it is the correct coreinfo dump.
EDIT:
Changed a hard disk on my Ryzen 5 box, installed win 10 (yuck) and did a coreinfo dump - see below.