coondoggie writes to mention an article at NetworkWorld about the outsider status of Ethernet in some high-speed data centers. From the article: "The latency of store-and-forward Ethernet technology is imperceptible for most LAN users -- in the low 100-millisec range. But in data centers, where CPUs may be sharing data in memory across different connected machines, the smallest hiccups can fail a process or botch data results. 'When you get into application-layer clustering, milliseconds of latency can have an impact on performance,' Garrison says. This forced many data center network designers to look beyond Ethernet for connectivity options."