@InProceedings{thakur:evaluation, author = {Rajeev Thakur and William Gropp and Ewing Lusk}, title = {An Experimental Evaluation of the Parallel {I/O} Systems of the {IBM~SP} and {Intel Paragon} Using a Production Application}, booktitle = {Proceedings of the Third International Conference of the Austrian Center for Parallel Computation (ACPC)}, year = {1996}, month = {September}, series = {Lecture Notes in Computer Science}, volume = {1127}, pages = {24--35}, publisher = {Springer-Verlag}, earlier = {thakur:evaluation-tr}, URL = {http://www.mcs.anl.gov/~thakur/papers/io-eval.ps}, keywords = {parallel I/O, multiprocessor file system, workload characterization, pario-bib}, abstract = {We present the results of an experimental evaluation of the parallel I/O systems of the IBM SP and Intel Paragon using a real three-dimensional parallel application code. This application, developed by scientists at the University of Chicago, simulates the gravitational collapse of self-gravitating gaseous clouds. It performs parallel I/O by using library routines that we developed and optimized separately for the SP and Paragon. The I/O routines perform two-phase I/O and use the parallel file systems PIOFS on the SP and PFS on the Paragon. We studied the I/O performance for two different sizes of the application. In the small case, we found that I/O was much faster on the SP. In the large case, open, close, and read operations were only slightly faster, and seeks were significantly faster, on the SP; whereas, writes were slightly faster on the Paragon. The communication required within our I/O routines was faster on the Paragon in both cases. The highest read bandwidth obtained was 48\,Mbytes/sec., and the highest write bandwidth obtained was 31.6\,Mbytes/sec., both on the SP.} }