Benchmarking Parallel I/O Performance for a Large Scale Scientific Application on the TeraGrid

This paper is a report on experiences in benchmarking I/O performance on leading computational facilities on the NSF TeraGrid network with a large scale scientific application. Instead of focusing only on the raw file I/O bandwidth provided by different machine architectures, the I/O performance and scalability of the computational tools and libraries that are used in current production simulations are tested as a whole, however with focus mostly on bulk transfers. It is seen that the I/O performance of our production code scales very well, but is limited by the I/O system itself at some point. This limitation occurs at a low percentage of the computational size of the machines, which shows that at least for the application used for this paper the I/O system can be an important limiting factor in scaling up to the full size of the machine.