>Is there possibly another processor type, NIC, and or machine that would be much >more efficient at handling this kind of traffic (packets per second, not >throughput)?
It's not OpenBSD but I recently saw this presentation, might be worth a read and it's links in terms of giving you a general insight as to what some people are doing to push the limits of opensource routing. http://ripe61.ripe.net/presentations/127-presentation.bengt.gorden.pdf