It's not throttling, per se; the M1 prioritizes its efficiency cores when off mains power, and the performance cores when on mains power.

When unplugged, it engages the performance cores as little as possible. You should be able to run `powermetrics` on an interval while running a high-intensity task to confirm; the performance cores pin first when on mains, then ramp up the efficiency cores, and the opposite happens on battery.

It's a big difference because the efficiency cores max out at about 2W draw, and the performance cores max out at around 18W. There's a big incentive in battery life to rely on that behavior.

I'm not sure yet if it's tunable, macOS doesn't make that a transparent behavior where you can just tweak it at will.

The Air will throttle if under full load long enough, but it's still mostly just ramping down the performance cores to stay cool.