Here is how I fix power consumption ERROR & device set power mode failure when adding multiple GPU with Nicehash.
This solution works for me using BTC-S37 motherboard and mixed 10 & 16 series GPU's so hoping that it will help you guys if you are same error with your mining rig.
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Disclaimer:
This video is no shape or form of any advice, it is strictly intended for entertainment purposes only, thank you.