ZSTD compression by default


We’ve been pioneering and supporting the addition of ZSTD compression to Nix since 2018.

In November 2021, Nix 2.4 was finally released with ZSTD support.

As of today, the Cachix 1.1 client will compress any pushed binaries using zstd by default, which can be reversed back to XZ compression in the binary cache settings.

This will significantly speed up pushing, as it was previously capped at around ~3-5mbit/s due to XZ compression hitting CPU per-core limits.

Using ZSTD, you should be able to push with a ~100mbit/s, while increasing the storage size by no more than 10%.

Please bear with us as we’re rolling out necessary changes to unlock the limits of uploading speeds in the next weeks.

On top of that, decompression should also see a 10x fold improvement, so in case you’re doing a lot of downloads, they should be more or less at I/O speeds now.