SHARCNET is a collaboration of 14 universities, colleges and research institutes in southern Ontario, and so is kind of like the Teragrid, only farther north. The model is a cluster of machines linked by a fiber optic network, and it’s growing from 800 to 6,000 processors.
The hardware is primarily HP ProLiant servers with Opteron processors in four different clusters with different interconnects, including a 1000-processor Myrinet cluster and a 1,500-processor Quadrics cluster.
Quadrics has a release with more info, and HPCwire has some coverage as well.