> Zero-copy mbufs get more advantagous as the size of the MTU increases.
> NetWare file server performance is a good example of how ring zero operation
> of a network application can make a difference in overall system
> performance. (i.e. a 486 running NetWare can support a 1000 users, whereas
> other ring 3 operating systems cannot).

You can only do this is the system is dedicate to a single protocol,
otherwise you don't know which buffers to put the data it.

There are a whole pile of brain-dead 'optimisations' that have been
done to ethernet cards in order to improve the performance of
certain netware benchmarks.  The usually use large amounts of
cpu time, requiring multiple interrupts per packet.  Their
'raison d'etre' is that netwars uses/used 512 byte ethernet
packets and a credit of 1 (ie every packet is acked from the
application layer).

OTOH if you ran a sensible protocol and sensible benchmarks
then 'transactions/second' is a much better measure of
server performance than 'response time.


	David

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