And one way or another, it's really quite trivial regardless. Sure, it's a neat line to throw in your ads to say you have the most powerful console on the planet or whatever, but at the end of the day, that doesn't mean a damn thing to anyone unless you have games that realize that in a meaningful way.
Don't worry, both companies will find a way to make the claim.
Let's say one have 0,5Tf more then they can call it, or their RAM is a little faster or bigger, anything they will use to claim the prize.
Although Sony with PS4 didn't use it in any ad, they let the games show it. MS was the one that brought the attention to themselves when they said that no way in hell they would let Sony have a console 50% more powerful or that the resolution would be different.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"