Shutting Down Clear Linux OS

What optimizations did they do that had the biggest effect? can they be brought into the mainline linux kernel and distros?

Mostly it's just compiling everything correctly and getting the most juice out of transparent hugepages.

I could be wrong but I think they used icc (Intel's c compiler) for most/everything?

Yeah, but there is something else here too... I used cachy for a heartbeat and it advertises the same benefits; it just felt slower (notably on boot) Maybe it was just all the graphical load screens.

There's something clear had that made it feel modern, familiar and boring (which might not be for everyone) 90% of my tasks were in vscode devcontainers so kept things simple and out of the system for the most part.

I don't think they build any part of it with icc, the world's worst compiler. They do not even offer icc as a package.

Sounds like bloat removal and minimalism.

Clear Linux's performance came primarily from function multi-versioning (CPU-specific optimizations at runtime), aggressive compiler flags (-O3, LTO, AutoFDO), kernel tweaks, and a stateless design that minimized I/O overhead.