Or the benchmark is broken. Considering that the whole Kepler lost performance thing was widely disproven as an AMD fanboy myth, AND there Maxwell architecture is proven to be 1.5-2.0X more efficient that Kepler, I really wouldn't pay any attention to this so called 'benchmark'.
Why dpo some people find it so hard to understand that Nvidia made a massive increase in performance per watt with Maxwell when all the facts are there to see in plain daylight.
Thanks but Il stick with option one, nvidia held back the 780.