tar under SCO Xenix

[Robert R. Kessler]

We are running on a PS/2 Model 80, using SCO Xenix 2.2.x.  We have an
Arnet Smartport from which we run a half a dozen terminals.  The problem
is that when someone does a tar (to our Mountain tape drive), all of
the devices connected to the Arnet board hang up.  So, we have to have
everyone log out, do the tar, then everyone logs back in.  SCO claims
that tar uses so much of the system resources that the Arnet board
gets lost.

Is this true?  Has anyone experienced anything similar.

B.