I don’t think distros like sid or rawhide are worth it for daily use, they’re more geared towards developers to adopt changes early.

I’ve been researching for a long time upon the topic of performance and distros, and my conclusion is that there are only 2 rolling release distros worth your time: arch (big community and very helpful wiki) and tumbleweed (if you want both stability and rolling release without a hassle this is the way)

the rest are either based on arch, are a sort of testing ground for the main spin or are just niche, like gentoo

from the above, compiling the kernel will have the greatest impact, and like I said, really easy to setup a kernel like tkg. in short, you clone the repo and just run a console command, makepkg -si

after the compilation is done, you have your kernel! the rest is a matter of setting up your bootloader, afaik for grub it’s automatic but I use systemd-boot so I had to add the entry manually. that takes 5 minutes at most

applying the said optimisations is trivial as well, you don’t have to know pkgbuild or gcc for that. tkg made sure that anyone can do it, the pkgbuild has plenty comments to explain which line does what and you only have to modify one line to add optimisations. I’ve never compiled kernels before compiling linux-tkg but it was easy to figure out. but all if this only applies to arch

I also disabled CPU mitigations and SELinux, that’s a couple of fps for a more vulnerable system, but I’ve been rocking this way for 3 years or so and got no problems whatsoever, just be careful when you use the AUR if you go the arch route

and don’t listen to people saying whether it matters or not, you should try it yourself first and then judge which is the case

1. choose a rolling release distro (either arch or openSUSE TW) or leading edge point release like fedora
2. compile the kernel yourself with march=native, LTO, O2 or O3 (requires benchmarking but O2 is a sane default), apply patches if any, optionally choose a custom scheduler. linux-tkg is good for this and really easy on arch since it has a PKGBUILD written for you
3. compile everything else that is important for performance: RADV/nvidia-dkms, proton (maybe), etc
4. run games in gamescope without a DE/WM (like the steam deck), try performance governor and/or gamemode

I’m pretty sure that’s it, with this setup you will squeeze every single digit of FPS you can

otherwise, go with openSUSE since their packages are compiled with x86-64-v3 support, -O2 and LTO which seems to give it an edge in benchmarks

you can convert them to ISOs and use it like any other image