(In reply to Andres Rodriguez from comment #2)
> > FWIW, Andres Rodriguez reported similar symptoms with a Ryzen system on IRC,
> > and raising voltages / disabling Cool'n'Quiet / disabling C6 states fixed
> > them for him.
> 
> I raised the memory and the core voltages specifically. The other voltages
> like SoC were left untouched.

I didn't have these symptoms in arch or ubuntu 16.04 LTS, only when using this
driver/kernel combination (which is only one that keeps both monitors usable).
Long compilation jobs don't cause system freezes either.