lz4: what is the max ultra-fast compression level? From `man lz4`: --fast[=#] Switch to ultra-fast compression levels. The higher the value, the faster the compres‐ sion speed, at the cost of some compression ratio. If =# is not present, it defaults to 1. This setting overrides compression level if one was set previously. Similarly, if a compression level is set after --fast, it overrides it. So what is the max ultra-fast compression level? Is it the same (12) as for compression level?

It’s currently 65537, as determined by the `LZ4_ACCELERATION_MAX` constant.

See also the library documentation for “fast” compression.