Ryzen 5900X update
As I mentioned in my previous post I received one Ryzen 5900X CPU. I have replaced one of the Ryzen 3900X with it. Before swapping out the old CPU I did a BIOS update to get the latest AGESA (126.96.36.199) to support the Ryzen 5000 series. The Linux kernel doesn't like it. When it boots up it throws quite a few of these messages:
EDAC amd64: Error: F0 not found, device 0x1650 (broken BIOS?)
It still manages to start up though. I haven't tried doing any crunching with it.
From internet searches it would seem there are upstream patches for device 0x1650 to the EDAC but I'm not sure what kernel one needs to be running to get it. The machine is running a 5.8.10 kernel. I tried 5.9.6 from Debian bullseye but that didn't help. There is a 5.9.9 in testing which I haven't tried. If you run Linux check you can get a (very) recent kernel before you install your nice shiny new Ryzen.
Update 1 Dec 2020
I should point out that the machine still works despite the 24 EDAC errors above.
I have raised a bug with Debian but haven't had any response. I don't know which kernel will contain a fix. I tried the 5.9.9 kernel and that didn't help.
Debian have an upcoming release of bullseye, expected in March 2021. The 5.10 kernel has been listed as an LTS (Long Term Support) version so I wouldn't be surprised if they put the 5.10 kernel into bullseye and hopefully it contains the necessary patch.
Update 19 Dec 2020
Debian closed the bug. The patch is in the 5.10 rc7 kernel. While 5.10 has been released by the kernel team it had a couple of bugs with the RAID code so they released a 5.10.1 already. Debian experimental have this at the moment and I expect it will be pushed up into bullseye in time for its release.