According to the latest reports NVIDIA launch their Volta GPU architecture in Q3 2017. If you remember, according to NVIDIA’s own road-maps, Volta was expected to launch around early 2018. The report goes on to say the Volta products, apparently marketed to be the GeForce 20-series, will see an early launch due to market demands, and NVIDIA intention to further increase pricing of its products through a new-generation launch.
Now obviously we regard these reports as just rumors for now, so take them with a grain of salt. It would be an interesting move for NVIDIA as they recently just announced their GeForce GTX 1080 Ti and TITAN Xp graphics cards. I would say the only reason NVIDIA would pull the Volta trigger early is to steal the thunder from AMD who is expected to launch their Vega GPU in Q2 2017.
Volta will more than likely make use of HBM2 or GDDR5X memory. It has also been rumored that NVIDIA will be building Volta on the cutting-edge 12 nm process.