for amd i read that asrock is usually the go to if you need something that has working ecc support.
but the problem is, for AM5, asrock was in the news for having issues with the 9800X3D cpu.
But there is now newer info. Wendel could not find the issue. So the assumption here was, maybe there has been a motherboard revision that fixed the issue. I think he mentioned asrock went back to previous suppliers for the components or some such, and maybe that fixed something?
Anyway, how i built my own truenas server may not be ideal. others suggested i don’t over spent on the cpu and motherboard.
so what i got was something similar to a desktop pc build. for motherboard i went with a msi B650 tomahawk.
This is the case i got. rm41-h08 silverstone 4u
i put it inside this open floor rack which also contains my other networking equipment like 24 port switches, router and above a wifi ap
my build didn’t use ecc ram however.
my build log thread for this is here. it’s pretty long. along the way others posted suggestions. this was in 2024 so might be slightly outdated, but maybe you can get some ideas for yourself based on comments by others?