[Tulip kicking up the when-to-start-sending knob.]

> This happens minutes after the machine is up with only the most minor bit
> of traffic on the wire.  After it has step to "store-and-forward" there is
> no further such changes.

When/if that happens depends upon the speed of the PCI/memory interface 
on your system.

The machines I normally work with don't go through that dance until 
I put a lot of network traffic through the Tulip, and even then it 
probably needs some other PCI work to provoke it.