Last week I moderated a webinar entitled Optimizing Performance for HPC: Part 2 - Interconnect with InfiniBand. It was a great presentation with a lot of practical information and good questions. If you missed it, it will be available for a few months, so you still have a chance to check it out. As part of the webinar, Vallard Benincosa of IBM, mentioned that the speed of light was a becoming an issue in network design. In engineering terms, that is refered to as a hard limit.