Infiniband vs GigE
GigE usually uses TCP/IP - and this protocol, while tremendously redundant & wonderful for convergence, is not terribly efficient at higher capacities.
Infiniband is a beautiful thing for high performance & clustered databases. Clustering memory caches between nodes requires high bandwidth and low latency - otherwise performance & scalability is limited.
I would have been interested to see a comparison between Voltaire and SUN as far as Infiniband switches in terms of capacity, size, and latency on a flattened network... instead of only Cisco.