Update: Running with the RX 560 installed resulted in a day of frequent issues where the display locked up and I had little option but to reboot. Happened perhaps a dozen times over the course of the day. I noticed various screen artifacts, but also noticed some fairly long periods - over an hour - where everything seemed to be working fine. Looking through the logs it appears that there is "VM Protection Fault" happening. For now I've pulled the card and gone back to a nice stable system using the onboard HD630 graphics. So much for working out of the box. I'll take another crack at it in a few days, but for now need to get some work done.