Each node of Cornell's Velocity is a 64-quad 500 MHz Pentium III Dell PowerEdge server. The diagram below depicts a simple computational cluster. The head node is usually the only node of the cluster that can communicate with the outside world.
Computational nodes are usually identical.
Cluster Interconnects High-Speed Interconnects Vendors Giganet. For more information on VIA, see the Virtual Interface Architecture Web site. Myrinet networks can scale to tens of thousands of hosts, with network-bisection data rates in terabits per second. Myrinet can also provide alternative communication paths between hosts. The link and routing specifications are public, published, and open.