[telendram]

A little known fact is that parallel XZ do compress worse than XZ ! I measured pixz as being approximately ~2% worse than xz. That's because input is split into independent chunks.

In comparison, the 0.8% of zstd looks like a bargain.

[shmerl]

Is 0.8% with maximum compression? It's surprising the difference is so small.

[telendram]

0.8% is with Arch's default settings. It's fairly strong, but not the strongest, to preserve cpu during compression.

zstd is used at level 20, but it can compress more. Levels can go up to 22, and (complex) advanced commands are available to compress data even more.