Ref earlier posts about the newer adrenalin drivers.

I'm now running 18.3.4 (https://support.amd.com/en-us/kb-articles/Pages/Radeon-Software-Adrenalin-Edition-18.3.4-Release-Notes.aspx) and it works nicely, just remember to use compute mode. Seems like the old beta blockchain drivers still performs a few % better though, but with less stability