Soundwave on 26 July 2016
If it can somehow run 400-500 GFLOP in portable state, it could probably run PS4 games at 960x540 resolution (1/4th the pixels).
Home dock could then bump that up to 720p-1080p.
That wouldn't be bad, but the Tegra X1 at 500 GFLOP runs pretty hot apparently, like 20 watts, now a die shrink to 16nm and more efficient Tegra X2 could bring that down considerably.
Lets say 50 GFLOPS/watt ... yeah maybe I guess. The battery for this thing will have to be quite large but the Wii U tablet was monstrous too.
