Thank you for sharing this, it's interesting - I've also gotten the impression (but lack citation) that Intel E cores are targeted at thermal isolation instead of power minimization as the M1 may target.

This is front of mind for me since reading a Cloudflare blog regarding AVX-512 instructions invoking dynamic frequency scaling to manage power/thermal capacity on chip. (https://blog.cloudflare.com/on-the-dangers-of-intels-frequen...)

If this is happening on Xeons, it's probably happening on consumer dies as well, in addition to other non-obvious power/performance optimizations. Perhaps this is why Alder Lake is pumping up the TDP[1]?

edit: [1] https://news.ycombinator.com/item?id=29106860

> They move everything that isn't foreground to an efficiency core, which is awful for compiling or video processing.

Windows has had that (foreground boost) for a long time, Intel probably piggybacks on it. It'll be interesting to see how it will behave on Linux, which AFAIK never had that mechanism (except perhaps on Android).