Zstd also has a multithreaded mode. On the CLI `zstd -T0` tells zstd to use all available cores.
I'll get a small benchmark script for that done over lunch. Come back here later.
Is this a continuation from previous message ? Because multithreading mode of zstd doesn't impact its compression ratio. It's actually an interesting property of zstd : whatever the nb of threads used, the compression ratio remains the same (aka. reproducible).