When limited to 5 watts, the Ryzen HX 370 works pretty darn well. In some low-power user cases, my GPD Pocket 4 is more power efficient than my M3 MBA.

We are going to need to see some numbers for your claim. That’s not believable.

A 8.8" screen takes a lot less power.

When you say efficiency, I assume you’re factoring in performance of the device as well?

Maybe run Geekbench 6 and see.

I am not the original commenter; but they said "low-power user cases" i.e. very much not when running Geekbench; rather when it is near idle.

FYI, AMD chips are notoriously bad at idle.

We will need some citations on that as the GPD Pocket 4 isn't even the most power efficient pocket pc.

Closest I've seen is an uncited Reddit thread talking about usb c charging draw when running a task, conflating it with power usage.

How about single-core performance?