[PATCH 0/5] ZSTD compression support for OpenSSH

Steffen Nurpmeso steffen at sdaoden.eu
Tue Sep 8 23:06:31 AEST 2020

Sebastian Andrzej Siewior wrote in
 <20200908073415.ymmao6fcemn5hqns at flow>:
 |On 2020-09-07 11:21:13 [+1000], Darren Tucker wrote:
 |> The zstd part would be a larger discussion because we would need to
 |> either carry it as a Portable patch or have zstd added to OpenBSD
 |> base, and I don't know if that would be accepted.  Do you have any
 |> performance numbers for zstd in this application?
 |A key stroke is here 10 bytes of raw data which zstd compresses usually
 |into 10 bytes while zlib manages to squeeze it into 5 bytes. This leads
 |to better compression ratio for zlib in ssh's accounting (visible in
 |verbose mode after connection terminates). The data length, that will be
 |transferred over the wire, is the same for 5 and 10 bytes data after the
 |crypto part (with padding and so on). 

Then something must be wrong on the configuration side for sure.
I personally have switched all possible private use cases to zstd
years ago, in can be configured to be tremendously fast, faster
even than lz4, no?, or compress almost as good as xz, it depends
on the data, xz can surely outperform it in size.
On the decompression side zstd is just tremendously fast.
And all in one algorithm.

|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)

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