[integricho]

After reading these comments, I can't help but wonder, what is the benefit of Zstd over lz4? Why didn't they switch to lz4 if it was the speed of the algorithm that they favored even with marginally worse compression ratios?

[ncmncm]

Where Zstd will reduce, say, 3x, Lz4 reduces only 2.5x. This doesn't seem very different until you look at it from the other end: my .zst file is 3.3 GB, but the .lz4 would have been 4 GB, which is 700 MB more.

Was a time when 700 MB mattered; it was as much as you could get onto a CD.

So, there is a place for each. I would set up the process to use Lz4 when testing, and Zstd for actual delivery to download archives.

In some circumstances, particularly when using a shared file server, Lz4 can be quite a lot faster than writing and reading data uncompressed.

[isatty]

Guessing that 0.8x size increase for 1300% speedup was worth the tradeoff but maybe ≥1.5 size increase or more was not (especially considering a 1300%->2000% increase is not going to be user visible for 99% of the packages).

[TJSomething]

It's not 0.8 times size increase, it's a 0.008 times size increase, since the unit is percent. The latter seems pretty marginal to me.