The cards are just not designed to make use of DX12 overall. The 1000 series received small tweaks, but nothing major. In most games, current Nvidia cards receive either no benefits or very small benefits from DX12. In a few games, performance is lower. With that said, AMD currently doesn't have a good competitor for the 1070 and 1080. The 1070 is still a good card, it has a lot of raw power. It might not be the best long-term upgrade if looking forward with DX12 games, but it is currently performing very well in present games. AMD next cards still have a relatively vague release date, simply aimed at the first half of 2017. If they have equal DX11 performance to the 1070 and 1080, they'd be big winners in DX12. The issue is having to wait for cards which may or may not be good. But it's nearly guaranteed it'll lead to lower prices for the 1070 and the 1080.