[Klinky]

You can do more power optimizations with efficiency cores than the performance cores. There are power tradeoffs to get max perf. You can significantly reduce vcore if your max frequency is much lower. Cache is also power hungry & takes up space.

[wtallis]

Early indications are that Zen 4c actually requires significantly higher voltage for the same clock speed as plain Zen 4 cores (though still a lower voltage than Zen 4 at speeds far beyond the reach of Zen 4c). All the savings AMD gets by targeting ~3.5GHz peak rather than 5+ GHz has been put into shrinking the core area: https://zhuanlan.zhihu.com/p/653961282

[deagle50]

It seems 4c requires .1v more through most of the clock speed range. It's purely a cost and density play.

[Klinky]

interesting, I wonder why. I guess it's saving via current reductions despite higher vcore.

[treprinum]

5c should be the same as 5 but with a smaller cache (unlike Core vs Atom distinction in Intel CPUs). I'd rather have a CPU full of 5c than a mix of 5 and 5c.