I have 16 rigs with this PSU, using 3 cables to power 6 gpus.. havent had any issues. What are your power limits set to?
Power limit on the cards? Its an AMD rig all cores run with 1150 Mhz the entire rig consumes 530 Watt ( will be extended in the future). The consumption can really not be a problem especially considering that the 850 PSU just works fine and powers all 6 cards. Just replacing the PSU ends in only 5 gpus starting.
I also dont believe that the PSU has a technical problem as everything else just works fine ( runs stable for 3 days on a test machine)