> Are these phone processors really as compute-pet-watt efficient as a regular data center processor?

I have no numbers to back up my argument, but smart phones are very power efficient by their nature are they not? I can play a 3d game, with impressive graphics, on a tiny device powered by a battery... With very little heat generated.

If your goal is to run LLM inference on a gpu in a power efficient manner, I bet a smart phone is a good place to start.