How's the ECC RAM support with the 3000 series?
At this point the Asus Pro WS X570-Ace ( https://www.asus.com/Motherboards/Pro-WS-X570-ACE/ ) appears to be the only x570 board with certified ECC support.
The Gigabyte X570 AORUS XTREME (as another example) says in the specs
> Support for ECC Un-buffered DIMM 1Rx8/2Rx8 memory modules*
* ECC is only supported with AMD Ryzen™ PRO-series CPU.
Hmm.
My only complaint would be the lack of detailed change logs, which are often only a single bullet point.
Their are also other issues that should be fixed but haven't.
I'm not sure about Asus' X570 line since they market a board with explicit ECC support, but their lower-end and mid-tier X470 boards supported ECC. Their higher end boards -- curiously -- did not.
You can generally tell if a board supports ECC by looking at the board's manual. If it supports ECC, it will be mentioned.