Since the Baffin circuit board doesn't mention GDDR5, it is likely using HBM on an interposer. 232mm2 would allow for far more than 2,560 SIMDs as well. Hawaii was 438mm2 and it had 2,816 SIMDs. If we assume a 50% die reduction with 14LPP, give or take, ~219mm2 is what Hawaii would take up. If we assume a 50% power reduction that's 137.5W (of course Hawaii made use of GDDR5 while Baffin appears to be HBM).
Baffin XT could have:
- 2,816 SIMDs (with higher shader efficiency)
- 64ROps
- 176 TMUs
- 4GB HBM
- New 4x Geometry Processors (Primitive Discard Accelerators)
- New Command Processor (Command buffer/Instruction prefetching for increased DX11/Single threaded performance)
- TDP lower than 130W
~219mm2 (and since it is likely 232mm2 then you could see room for the new Multimedia cores, larger caches etc).
That would make it quite the card for the price point in terms of performance per watt.
For Polaris 11, we could see a Greenland XT look like this:
- 4,096 SIMDs (with higher shader efficiency)
- 64ROps
- 256 TMUs
- 8GB HBM2
- New 4x Geometry Processors (Primitive Discard Accelerators)
- New Command Processor (Command buffer/Instruction prefetching for increased DX11/Single threaded performance)
- TDP lower than 160W
~350mm2 (Room for the new Multimedia cores, larger caches etc).
Architecture overhauls could account for +45% performance per clk over Hawaii and Fiji respectively.
We could also see changes in the ROp count but that would take a shader engine overhaul. We might only see that with Vega 11.
Neither of these two would compete with GP100. This leads me to believe that Vega 11 is intended as an answer to GP100.