Just tested it, power efficiency works flawlessly. Thanks mate, I can finally ditch Wattman completely.
As I said, it might not even be a part of the Overdrive API. Also it's present only on RX400 cards afaik, maybe 300 series as well. It's...
Would it be possible to add the power effieciency control switch for RX400 series, or is it not a part of the Overdrive API?