Overhead of raw-mode shells (Bash, Zsh, Ksh etc)

[Stephen Cliffe]

Does anyone have any feeling for the overhead placed on a machine
by running the more modern shells that support command line editing. 

We would like to make either bash or zsh available to our students
and are a little concerned by the possible extra system overhead this
could impose due to the use of raw-mode and therfore conext switches
etc.

Thanks,

Steve.