From Anandtech's deep dive into the performance and efficiency cores in the A15, which are reused here in the M2.
Performance Cores:
>Apple A15 performance cores are extremely impressive here – usually increases in performance always come with some sort of deficit in efficiency, or at least flat efficiency. Apple here instead has managed to reduce power whilst increasing performance, meaning energy efficiency is improved by 17% on the peak performance states versus the A14. If we had been able to measure both SoCs at the same performance level, this efficiency advantage of the A15 would grow even larger. In our initial coverage of Apple’s announcement, we theorised that the company might possibly invested into energy efficiency rather than performance increases this year, and I’m glad to see that seemingly this is exactly what has happened, explaining some of the more conservative (at least for Apple) performance improvements.
Efficiency Cores:
>The A15’s efficiency cores are also massively impressive – at peak performance, efficiency is flat, but they’re also +28% faster.
The comparison against the little Cortex-A55 cores is more absurd though, as the A15’s E-core is 3.5x faster on average, yet only consuming 32% more power, so energy efficiency is 60% better.
Conclusions:
>In our extensive testing, we’re elated to see that it was actually mostly an efficiency focus this year, with the new performance cores showcasing adequate performance improvements, while at the same time reducing power consumption, as well as significantly improving energy efficiency.
The efficiency cores of the A15 have also seen massive gains, this time around with Apple mostly investing them back into performance, with the new cores showcasing +23-28% absolute performance improvements, something that isn’t easily identified by popular benchmarking. This large performance increase further helps the SoC improve energy efficiency, and our initial battery life figures of the new 13 series showcase that the chip has a very large part into the vastly longer longevity of the new devices.
https://www.anandtech.com/show/16983/the-apple-a15-soc-perfo...