>  This is a sparc5/170, so at the top end of the sparc5 range.

Somewhat faster than the systems I used to play with - 50MHz top IIRC.
> 
>  This is via a netgear 10/100 switch, and I can't easily perform
>  the tests while the machines are idle, so the numbers would
>  probably be a _little_ higher...

I'd blame the switch.
For throughput tests you need a hub (or something you can't afford).

 David

-- 
David Laight: david@l8s.co.uk