I've seen this be popular but I'm a little sceptical as to the effectiveness of their optimisations. Does anyone have some examples, anecdotes?

As shared elsewhere, I've used Arch Linux since 2017 sometime, and this year I replaced it with CachyOS as I was changing disks anyways and wanted to see what all the noise was about.

It's like a Arch brother that holds your hand slightly more, and have some "defaults" they nudge you towards in the docs, and some number-heavy software is slightly faster, maybe 10-15%, but overall it feels and works just like Arch Linux. To be honest, I don't notice a lot of difference and I think I'm as fine with Arch as with CachyOS, that's how little different there is between them.

Here are benchmark rounds of CachyOS against current Ubuntu and Fedora workstations as fresh as early November:

https://www.phoronix.com/review/cachyos-ubuntu-2510-f43

I've setup cachyos repos on arch and it does indeed feel snappier. I've not measured any performance, but I'd imagine it's negligible on my pretty new ryzen 9. Nonetheless, the process was fairly easy and so far nothing has broken because of that. If I were to actually care enough to test it, I'd also try just swapping the scheduler on the normal Arch kernel.

Just an anecdote but I've been running it for a few months now and at least for gaming it works well. Arc Raiders plays fantastically. There is an issue with one of my headsets that when you get in game the audio quality drops to dogshit but I think that's a bigger issue with the headset on Linux and not particular to Cachy.

I’m running CachyOS for a year now as my daily driver (non-work) on my ancient desktop from 2019 and ancient Nvidia card. It is very fast and smooth. I mainly use it to development using LLM sidekicks and it doesn’t break sweat. I use XFCE and just love how fast the experience is.

Anecdotically I'm using it since about 2 years on obsolete Kaby Lake Core i5 7500T & Core i7 7700T @35Watts in 1 liter Lenovo Thinkcentres (M910q tiny). Which have integrated HD630 Graphics.

Under Plasma/KDE. I just followed their defaults in the installer, which at the time were BTRFS for the filesystem, whith systemd-boot, and everything wen't well. The only thing which I would have done differently in hindsight would be the boot partition at 2GB, which seems wasteful when only about 50MB are ever used. But shrug?

What else, hrrm, the stuff is mostly clocked down to 800Mhz, because of the chosen scheduler, in spite of this nothing ever lags. Though the systems have 32GB RAM, that should help with that.

It's really smooth, even on that old 'crap', even mostly clocked down.

I also had it never crash on me with anything, neither single applications, or system hangs.

After upgrading with pacman -Syu I immediately clear the package cache with pacman -Scc, because I never ever needed that.

At the moment I'm considering to remove the pacman hooks into btrfs-snapshots, because I never needed them either. Seems like cargo-cult to me :-)

I also let it bitrot for up to 150 days, meaning no updates whatsover, and then lifting it up in one accumulated rush. Effortlessly. In the past, because I've been lazy and couldn't be bothered. Lately more often :-)

I didn't reboot in these long phases without updates. Just suspend to RAM. Which works every single time. And the system stayed always responsive.

Their ZRAM setup is usable by default. No fiddling necessary.

With this stability I dared to activate https://github.com/graysky2/profile-sync-daemon / https://wiki.archlinux.org/title/Profile-sync-daemon and never had any trouble with it so far.

At the moment I'm having fun discovering a new world of audio experience with https://github.com/wwmm/easyeffects

How could I live without that?!

(Don't worry, cores stay at 800Mhz with that playing YT in FF, or watching a movie with MPV)

At least on my hardware it's the DREAM.

Oh. Did I mention I don't game at all? With the exception of maybe some Freeciv in the browser...