A TitanX is 6.3 TFlops at stock speed of around 1000MHz but overclock it to 1500MHz and the Tflops are effectively 9.15.
The 1080 is running at over 1600MHz to get 9 Tflops. What does that say about the Pascal architecture?
It says that Nvidia designed Pascal to achieve high performance through high clockspeed. Nothing wrong with that. CPU's did the same with their long and short pipelines.
Only worry I would have, with the high clockspeeds, is the potential for coil-wine.