Would the performance of the mini be drastically different if they used the A7X instead of the A6X? Since the screen is smaller than the Ipad4 doesn't it require less power?
Smaller, with the the same resolution panel, means higher PPI, means smaller pixels, means you need more backlight power to achieve the same brightness.
A7X is on new 28nm process, by all accounts, it's a source of the iPhone 5S supply constraint.
Launching 2 new highvolume products on this already constrained process seems unlikely.
A6X on old process seems more likely, but it's not super power efficient. I imagine they need to work some engineering magic to achieve slim and battery life.
I suspect it's going to get thicker like IPad 3 Retina did.
----------
A7 has enough horsepower to run the retina without being an "x" version.
Interesting. So would the old A6 from the iPhone 5. It's at least as powerful as the A5X I think used in the iPad 3.
And it's low power. Interesting. Also that chip production line has no constraints on it like the new A7 line does with iPhone 5S and iPad 5. That makes a lot of sense.
I bet the iPad Mini2 Retina gets upgraded to plain A6. iOS7 will get further iPad optimizations, and it will continue to limp along. iOS8 will tax it, and it will have a short life like the iPad 3 had.