According to the story that was circling around the CES 2017 show, Nvidia was actually planning to reveal the GTX 1080 Ti at the show but has decided to delay it in order to wait for AMD's Vega -based graphics card and try to rain on its parade.
According to The Tech Buyer's Guru site, which cites "a friendly rep at the MSI booth", the GTX 1080 Ti graphics card is real and will be available from all Nvidia AIC partners, as soon as Nvidia gives the green light at the PAX East 2017 show.
This also means that the GTX 1080 Ti will probably be available from day one and it is also possible that partners got a green light to make custom versions.
In case you missed all the earlier rumors, the GTX 1080 Ti is likely to be based on the same 16nm GP102 Pascal GPU as the Titan X, but pack anywhere between 2560 and 3584 CUDA cores. It should also pack 10GB of GDDR5X VRAM on a 320-bit memory interface.
AMD's upcoming Vega 10-based graphics card performance was impressive at the show, but Nvidia's GTX 1080 Ti is certainly packing a lot of power as well.