The Intel 12th Gen Core i9-12900K Review: Hybrid Performance Brings Hybrid Complexityby Dr. Ian Cutress & Andrei Frumusanu on November 4, 2021 9:00 AM EST
CPU Benchmark Performance: E-Core
In this batch of testing, we're focusing primarily on the E-cores. Intel claimed that the performance was around the level of its Skylake generation of processors (6th Gen to 10th Gen, depending which slide you read), and we had to put that to the test. In this instance, we're comparing to the flagship Skylake processor, the Core i7-6700K, which offered 4C/8T at 91 W. We also did a number of multi-threaded tests to see where the E-cores would line up.
In order to enable E-core only operation, we used affinity masks.
In these few tests, we can see that the E-core is almost there at 4.2 GHz Skylake. Moving down to 3.9 GHz, perhaps something like the i7-6700, would put it on par.
Having a full eight E-cores compared to Skylake's 4C/8T arrangement helps in a lot of scenarios that are compute limited. When we move to more memory limited environments, or with cross-talk, then the E-cores are a bit more limited due to the cache structure and the long core-to-core latencies. Even with DDR5 in tow, the E-cores can be marginal to the Skylake, for example in WinRAR which tends to benefit from cache and memory bandwidth.