Now where things get interesting is that the "Efficient" cores are no slouch either. TechPowerUp reports the Gracemont cores of Intel's Alder Lake are faster than you may expect and that this will be how Intel may keep up with AMD's fastest Zen 3-based processors:
Intel in its Architecture Day presentation put out some astounding numbers that help support how 8 big + 8 little cores are able to perform in the league of 16 AMD big cores. Apparently, on "Alder Lake-S," the 8 "Gracemont" E-cores enjoy a lavish power budget, and are able to strike an incredible performance/Watt sweet-spot. Intel claims that the "Gracemont" E-core offers 40% higher performance at ISO power than a "Skylake" core (Intel's workhorse P-core for desktops until as recently as 2020); which means it consumes 40% less power at comparable performance.