First of all, I think it's important to state that the 'default' settings that distros ship with and thus you're met with right after a fresh installation try to target a sweet spot in which a lot more besides performance is considered; reliability, security, stability etc. However, depending on your workload and your hardware configuration, it's possible to have it more optimized towards performance through 'tinkering-means'.

However workload, metrics, system and hardware configuration provide so much variability that an exhaustive comparison between distros is just hard to do right. It's possible to find some on Phoronix (and ~~Reddit~~), but testing it yourself on your own hardware is a lot more valuable.

Still, it's possible to draw some basic conclusions based on the available data and common sense:

• Newer versions of the kernel generally have optimizations related to performance, especially for newer hardware. So -for performance sake- it makes sense to pick a distro that always tries to stay as close as possible to the latest kernel release.

• Overhead is in almost all cases detrimental to performance, so more minimal systems seem to score better. A lot of distros offer an ISO that's meant for minimal installations, so those are perhaps worth checking out.

• Compiling yourself (with performance optimizations) or using packages that have been compiled with performance optimizations in mind provide significant improvements that might be worth your time.

Beyond these three it becomes very murky, real quick. I guess (custom) kernel patches/optimizations are worth a mention, but you would have to benchmark it yourself on your own hardware to see if they're even worth the hassle (spoiler alert: some of them should, but it's best to stay objective and without any expectations regarding them).

I'd like to end this with naming some distros that might be worth mentioning in this discussion: Arch, CachyOS, Clear Linux, Garuda, Gentoo, Nobara and PikaOS.