https://bugs.freedesktop.org/show_bug.cgi?id=109955
--- Comment #25 from Matt Coffin mcoffin13@gmail.com --- (In reply to Mauro Gaspari from comment #24)
Hi, a bit frustrating eh? :) I have been asking around and it seems that RadeonVII and RX590 do not suffer those issues. Probably related to default clock speeds by manufacturers.
FWIW, I'm seeing this exact same issue, and I'm on an RX590.