As it turns out my Master (W7) and one xp64 farm unit have 'Jumbo Frame' as an option.
The two other xp64 farm units only have 'Maximum Frame Size' (both are set at 1514).
Could I set both of those to some HIGH number - perhaps similar to one of the 'Jumbo Frame' options given - i.e. 8 or 9KB MTU (as optioned in Jumbo Frames)?
Otherwise soundcard adjustments are my only option (or replacing the NIC's on the two farm units). Since there is no real guarantee of performances increases I'll likely not do that.
Thanks for your feedback.
Rob