It's not a matter of absolute numbers, but a question of die area, to some degree. You can either spend X amount of area on a "big core" that can clock all the

It's not a matter of absolute numbers, but a question of die area, to some degree. You can either spend X amount of area on a "big core" that can clock all the way down to idle (where it will spend most time) and all the way up to its max perf, or you can spend a fraction of X on a smaller core with a much, much smaller relative surface area, and get the same performance at idle or near-idle tasks. It just won't be able to scale "up" to max perf. But the net gain is you've saved a significant amount of area, and that translates to better TDP and thermals. The goal is to reap this benefit while also having "big cores" for the throttle-up phase, so you need both. There's a lot of talk about "background tasks" that do light, but necessary processing in asymmetric multicore setups like this; for example on macOS Spotlight performs background indexing continuously, this is a great fit for a "small core" like in the M1. There's no amount of idle clocking you can do to match the perf-per-watt here. Similarly, there is also talk of "dark silicon" and "increasing heterogenous systems", like hybrid designs. But these are all the same problem, really: modern designs are not about having the most powerful components, but the correct blend of components to maximize the work-per-watt you can achieve. You can't just throw "more transistors" at every single design anymore and get free wins on all fronts 1 year later when transistors shrink.