Fastest connection

[Graaf_van_Vlaanderen]

I'm always using 'ssh' to login and do some stuff on a my servers. From time to time I'm using graphical applications. Firefox for instance runs as smooth as directly on my PC. However certain other applications seem to work slower, especially when there is some interaction: gnuplot or gimp. When this happens the ssh daemon is very busy.
Are other logins like telnet, rlogin, rsh, etc faster due to the absence of encryption or is this difference hardly noticeable.

 

[DutchDaemon]

Do you have compression enabled in ssh? Encryption certainly has impact, but with compression added it may a be quite some overhead.

 

[Graaf_van_Vlaanderen]

Do you mean the '-C' option?
I remember I checked this:

     -C      Requests compression of all data (including stdin, stdout,
             stderr, and data for forwarded X11 and TCP connections).  The
             compression algorithm is the same used by gzip(1), and the
             ``level'' can be controlled by the CompressionLevel option for
             protocol version 1.  Compression is desirable on modem lines and
             other slow connections, but will only slow down things on fast
             networks.  The default value can be set on a host-by-host basis
             in the configuration files; see the Compression option.

 

[DutchDaemon]

Either -C on the command line, or 'Compression' settings in ssh_config / sshd_config.

 

[SirDice]

Are other logins like telnet, rlogin, rsh, etc faster due to the absence of encryption or is this difference hardly noticeable.

If you have recent hardware the difference is hardly noticeable. Besides the inherent insecurity you can't tunnel X over telnet, rlogin, rsh etc.