What do you get when you put together top scientists from National Center for Supercomputing Applications (NCSA), Boston University, University of Kentucky, and the Ohio Supercomputer Center (OSC) to design and write an on-line course? The answer is a top notch Performance Tuning on Clusters course. “In the PACS Training group, we have great breadth in expertise and experience. The Alliance community embraced cluster computing and set the standards for academia and industry alike—and this course is a product of that leadership,” said Leslie Southern, PACS Training Group Lead. The course developers looked to their sites’ experiences with cluster computing when selecting the topics for the course. The topics are not only theoretical, but also practical in nature. The on-line tutorial, located at, http://webct.ncsa.uiuc.edu:8900/public/PTCLUST/, includes the following topics: • Cache Tuning • Timing & Profiling • General Tuning Techniques • Architecture Dependent Techniques • Cluster Issues • Optimizing Parallelism for Cluster Architectures Compiler Flag Summary for Intel Compiler Suite (Appendix) • Compiler Flag Summary for Portland Group Compiler Suite (Appendix) “We wanted to develop an on-line tutorial that would enable users to maximize their time and efforts on their clusters, especially when parallel processing. Based upon initial feedback on the course, we have accomplished that goal,” said Southern. The Performance Tuning on Clusters on-line tutorial was developed by PACS Alliance partners NCSA, Boston University, University of Kentucky, and OSC. NCSA’s Ian Brooks led the course development team.