Both these cards will have 8GB, no way would Nvidia release a 4GB now lol! From everything I've read, 1080 will have 8GB GDDR5X and the 1070 8GB GDDR5. That's a safe bet now I'd say. What will be interesting is price point and how much more the 1080 offers over the 980Ti. I am guessing 10-15% minimum... if it isn't at least that, they won't be selling very many given how well the 980Ti has sold. People will just hold out for HBM2 cards.