The Core-Diameter

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.

I started to think about this limit and how it would effect the size of clusters. I did some back of the envelope math to get an estimate of how c (the speed of light) will limit cluster size. I want to preface this discussion with a disclaimer that I thought about this for all of 20 minutes. I welcome variations…

1. Smashing (and) the HPL Benchmark
2. Small Hardware and Big Software at SC10
3. High Performance Community
4. Round Two of the OpenMP-MPI Smack-Down
5. Smart Clusters: Intelligence Is As Intelligence Does