> So it's a headless passively cooled server version of the R9 Fury X? I figured this was a faster and improved version.

Almost. My guess is R9 Nano [1] given the same 8.2 Tflops (SP) Flop rate [2].

[1] http://www.anandtech.com/show/9621/the-amd-radeon-r9-nano-re... [2] http://images.anandtech.com/doci/10905/AMD%20Radeon%20Instin...

> Not sure if AMD is going to go all HBM on all it's high performance GPUs in 2017, or only offer one or two models with it.

It would make perfect sense to have some GDDR5X-based medium-range GPUs. HBM2 will be expensive, too expensive for the top of the medium range (and the same applies for NVIDIA). GDDR5X has plenty of room for improvement over GDDR5 and by next year they should have it figured out better.