I'm pretty sure a standard Carrizo APU only uses about 35 watts, has a 4 core excavator CPU, that runs at 2.4GHz and there's a 16ROP GPU that packs about 819GFlops.
Nintendo could get AMD to design a SOC with 2X that level of hardware, for a 1.6TFlop 8 Core CPU that would basically trounce the 8 Core Jag in XB1 and PS4 running on 70 watts for the SOC alone.
Form factor wise Nintendo could probably have a system about 2/3rds of the size of PS4 (slightly fatter than Wii U, tiny bit wider), but packing a better CPU and a GPU close to PS4.
PS4 doesn't suffer any cooling or noise issues and the thing is very sleek, if Nintendo wants PS4 levels of tech, but a smaller form factor the tech is available for that.
None of this rubbish Apple A9X junk is needed.
For the console that's all good, cost wise it would probably be pretty comparable to PS4 too.
The handheld could just use about 1/10th of the hardware, scale the resolution down from 1080p to 480p, reduce a few effects here and there, but essentially keep the same core experience.
I don't see why a 10 watt battery for a handheld isn't possible with modern tech, in a Wii U Gamepad sized package, at a reasonable cost.
