http://pages.di.unipi.it/farruggia/dcb/
Looks like Snappy beats both LZ4 and Zstd in compression speed and compression ratio, by a huge margin.
LZ4 is a ahead of Snappy in the decompression speed.
I have not researched this opinion much
The numbers I know about are wrong: zstd always beats gzip for compression ratio.
I will need to do my own testing.
It compresses about as well as lz4, but more slowly. It also decompresses more slowly.
It is faster than zstd -1, but compresses less well.
It is possible that it does better with certain kinds of data, but 12x remains implausible.
Apparently the current file format has suffix ".sz".
I have not researched this opinion much