they said there were features beyond Polaris . Could it be something from vega ?
One glib answer is that Neo presumably will still have a Trueaudio-like hardware block, which Polaris does not.
Possibly, it also inherits some of the compute and coherent memory tweaks of Orbis that Polaris as a discrete would not have.
I hope there is more detail about how backwards compatibility is handled, since there are points of conflict between Polaris and Sea Islands that don't show a trivial path to handling.
One oddity with Neo mode and standard mode relative to Polaris is what happens with the ROP count. The standard relationship between shader engines and back ends either changes to let Neo mode and its extra engines to be toggled off for compatibility reasons without deactivating ROPs, or Neo winds up having broader rasterization or pixel output.
Either way, it seems like there is going to be a difference, and preferably a difference in a positive direction.
The emphasis on hardware acceleration for what looks to be a standardized path for checkerboard rendering might include pipeline tweaks to better cull and filter with a known stride and alternating frame pattern. The extra front end and back end resources might be tweaked to provide resources or computation for the shortcuts (accelerated stairstep smoothing with spare resources?), maybe compression can be tweaked with the known pattern of writes and reads.
GCN has some amount of tiling already for its rendering, and I wonder if Vega will be going further in that regard. Some shortcuts from that might apply back when Sony is targeting an upscaling scheme instead of having to flesh out a more generalist implementation.
I'm curious to what extent Neo is like Polaris or Orbis, and how much that goes into Neo is attention and engineering that goes no further than Sony's platform. Good for Sony, but not lifting the GCN boat in arenas where console lowered expectations apply.