How are the 700 series not built without one of the key requirements to benefit from the new API? http://www.dsogaming.com/news/report-directx-12-to-be-exclusive-to-windows-10-nvidia-lists-dx12-compatible-gpus/ Nvidia says' that even the older generations like Fermi.
Like I said - Kepler and older nvidia GPUs lack Asynchronous Shaders. AMD has been building their graphics cards with this technology for years. Nvidia didn't include this tech until late last year on their Maxwell cards. DX12 can leverage this technology to improve performance up to 46%(though realistically it will likely be a bit less). Here is another link to help explain it: