Btw, if by "blockchain drivers" you mean ones from 23. august 2017, try latest adrenaline instead,
as original old blockchain driveers are known to draw more power
I meant
that drivers (Radeon Software Crimson ReLive Edition Beta for Blockchain Compute Driver Version 17.30.1029 (Windows Driver Store Version 22.19.659.0).
I have tried the Adrenalin Edition drivers a couple of times. But each time I got lower hashrate than with the blockchain drivers. Perhaps, I should try once again. Thank you for the hint.