I miss ATI

Isn't this the issue where they leave debug logging on by default in a fresh driver install? The fix to which is just an obscure switch in the Adrenalin driver, thus shutting off Window Composition event logging?

And this is why you should never auto update anything.

"Temporarily stopping AMD External Events Utility through services.msc eliminates the excessive writes" can confirm

the two workarounds explored in that article are to disable ReBAR in your SBIOS, which will net you a marginal perf deficit overall, or to disable EEU, which should generally be fine, but may break things like FreeSync under composed iflip (generally not seen much today)

These are both far from ideal. Hope to have a knowledge base article up soon.