Update from one of the demo authors:

"The Adam demo runs in 1440p at 30fps on a GTX 980, by the way :) See it running real-time at the Unity booth at GDC!"

https://twitter.com/robertcupisz/status/710160351568986112

So it's very likely that the YouTube video was rendered with far better hardware.

And one Titan X gives 6.6 TFLOPS, single precision (peak)

From the youtube comments that was also buddy pulling a guess out of his butt.

Was the commenter making it up.

Sure, but same info here: http://thenextweb.com/gadgets/2016/03/16/check-amazing-short...

Someone should ask though given another poster's comment below about the GDC demo of the editor where they were using a GTX 980.