Finally was able to get ahold of the Radeon Pro W5500 adapter (RDNA and Nav14). Shutdown one of the systems and physically installed the card in the 2nd PCIe x16 slot. There was an existing air cooled Radeon HD 6670 that I left in the machine because it had a HDMI port I could use for communicating with the system. W5500 only has 4 DP ports and I don't have a DP cable and monitor doesn't have a DP port. Anyway, pressed power button and nothing happened. Turned off power supply, unplugged power cord, replugged power cord and turned on power supply. Pressed power button again and system LEDs and lights just blink (should stay lit). Removed W5500 card and nothing happened when pressing power button. I assume, power supply was blown or damaged in some way. It is an 850W power supply but is about 5 years old. Bit the bullet, and took second identical system and removed old VGA card (W5500 comes with a DP to DVI cable. Didn't notice that right away) and installed new W5500 and system powered up fine. Tried to install latest AMD Pro driver and get compile errors during DKMS install. System recognizes the card (Firmware works) and clinfo installs and works but BOINC doesn't recognize the card (Driver not working). Most likely due to kernel being higher level than supported. AMD doc says driver is for CentOS 8.1 and I'm at 8.2 although both 8.1 and 8.2 use the 4.18 kernel. Difference is the ABI level. This is why I don't run GPU work. I suspect the solution is the 21.Q1 driver but it hasn't been released yet. Doc says it was due out on 2/10/2021 but it's not there yet. The card works and I'm able to attach a monitor to it and use as a terminal but that's it. Now just waiting for a new driver to be released.