I'm not knowing how much of this things are true, but isn't it ironic that AMD has more benefits from SMT because they have less pipeline optimizations (and similar), but exactly this pipeline optimizations (and similar) seem to be at least partially at fault for some of the Specter style attacks and make it harder to put more cores into the system (as this additional optimizations are likely need more silicon space...).
Sometimes I'm wondering if the best (but software side maybe impractical) design for (non Threadripper level) consumer PC's would be something along the line of.
- 1 single non SMT core with most advanced pipeline optimizations and highest clock speed which only always runs one thread pinned to it (many consumers tend to only run one "costy" applications with need for highest performance at the same time, e.g. a game main event loop).
- around this 4+ SMT enabled cores which are (mostly/reasonably) specter save and have less max. clock speed (other open applications, other threads from the current game, should be good enough for most applications)
- 1+ very low power cores which might have another arch (for the background maintenance tasks of the OS and programs like e.g. update jobs, slow long polling, always-on/connected features etc.)
- 1+ crypto core with integrated hardware security module, used to thinks like signing AES keys and similar (e.g. setup but not run TLS)
Through it's probably unrealistic as e.g. thermal regulations for high speed threads is optimized by "bouncing" the logical thread between cores and software
tends to not want to do things like write the background maintenance code for a different arch then the rest of the software, well phone OS probably could force this. Microsoft + Intel kinda can't.