TechPowerUp published Intel Core i9-12900K E-Cores Only Performance
A quote from the article:
With Alder Lake, Intel is betting big on hybrid CPU core configurations. The Core i9-12900K has eight P(erformance) cores and eight E(fficient) cores. We were curious and tested the processor running with the E-Cores only, to see how well they perform against architectures like Zen 2, Zen 3, Skylake, Comet Lake and Rocket Lake.Intel Core i9-12900K E-Cores Only Performance