I should have paid more attention. (c) Sounds like the CPU using the HBM as a cache for system RAM rather than drives on the system. Which sounds awesome, and would probably be really easy to do.
(b), is very interesting. In theory if they could get that working with the same scaling as the CPUs; Nvidia could actually be in trouble.
Unfortunately, even us we paid attention, and wrote it in this forum numerous times, got vilified. (even if the video is still there).
And I did show some understanding initially because, when Raja said those things for Vega, Ryzen was 2 months away and not many understood what he was talking about, including myself.
However 3 months after the Ryzen CPU launch, and 6 months after Raja's statement, you don't have to go away from this very thread to see the technical ignorance of many.
And sheer inability to learn.