Computer Science 400 Parallel Processing Siena College Fall 2008

There are several files to turn in for this assignment. They should all be submitted under a directory named lab6 that you submit using the turnin utility. Please use the filenames specified and be sure to include your name in each file.

Modify one of the matrix-matrix multiply examples that uses MPI for communication so that all three matrices exist only on the master process at the start and finish of the computation. Use MPI functions to distribute the entries of A and B, as needed, to the processes (include the master in the computation), do the multiplication, then use MPI functions to gather the result C back to the master.

• You will need a number of MPI communication steps. Explain each MPI call (what you need to do and why you chose that particular MPI call) in detailed comments in your source code.
• Run your program using 1, 2, and 4 processors of the FreeBSD nodes of the Siena cluster. Include the timings and your analysis of those timings in the README file that you include with your submission.
• Run your program on as many processors of the Worldwide Computing Lab systems as you can. Details about how to run at RPI will be made available in class on October 22. Include the timings and your analysis of those timings in the README file that you include with your submission.

Your submission should include your Makefile, your source code, and the brief README file that explains how to run your program, describes how and why you chose to parallelize your program, and describes and analyzes your timing results. Please do not include object files or your executable in your submission.