> On a performance-per-watt basis, Apple is still behind an Nvidia card with the juiced up power consumption, and when you dial back the power draw, Nvidia cards are miles ahead of Apple's silicon for performance-per-watt.

Do you have a citation on Apple vs nVidia performance-per-watt? I'm not aware of any benchmark that shows nVidia with a better performance-per-watt. Higher performance, sure, but performance-per-watt, not that I'm aware of.