Prove it.
Oh dear...
With Pascal/GP104 particulars out of the way, let’s talk about the cards themselves. “The new king” as NVIDIA affectionately calls it will be the GTX 1080, and will be their new flagship card. NVIDIA is promoting it as having better performance than both GTX 980 SLI and GTX Titan X. NVIDIA’s own performance marketing slides put the average at around 65% faster than GTX 980 and 20-25% faster than GTX Titan X/980 Ti, which is relatively consistent for a new NVIDIA GPU. Of course, real-world performance remains to be seen, and will vary from game to game.
http://www.anandtech.com/show/10304/nvidia-announces-the-geforce-gtx-1080-1070/2