6GB of GDDR5X working on 8800MHz
It appears that Nvidia's response to AMD's upcoming R9 590, in the form of GTX 1060 with GDDR5X memory, might actually end up slower than some previous GTX 1060 graphics card on the market, due to a lower memory bandwidth.
Possibly based on a cut-down GP104 GPU
It appears that Gigabyte could be working on a GTX 1060 graphics card that will be equipped with faster GDDR5X memory and a cut down GP104 GPU, and while other specifications are unknown, faster memory could give the GTX 1060 a fighting chance against the upcoming 12nm Polaris-based Radeon RX 590.
Too early for this memory
Volta is out for artificial intelligence, machine learning applications and it will be shipping in DGX 1 systems, mainly for deep learning and AI. The next Geforce will be a completely separate chip.
Too expensive, limited supply
Our well-placed industry sources have told us that we should not expect to see the HBM 2.0 based GPUs shipping anytime soon. Nvidia Pascal and AMD Polaris 10 / 11 will stick with GDDR5 memory for the time being.