Assignment 1

CS 540 High Performance Computing
Instructor: Jeremy Johnson
Due date: (Wed. Oct. 29 by the start of class) [Preliminary data should be obtained by class time on Oct. 22]

In this assignment you will empirically explore the performance of matrix multiplication. You will start with the code from Numeric Recipes (included here), explore several variants, and finally compare against high quality code from ATLAS or Intel's MKL library .

Numerical Recipes

• matrix.c
• matrix.h
• block.c
• timemm.c
• timeblockmm.c

Assignment Tasks

1. Determine the architectural features of your computing platform (clock speed, machine type, amount of memory, cache parameters, number of functional units, pipeline information). You should use various microbenchmark programs to gather this information (e.g. those that come with PAPI such as mem_info, MOB, Calibrator, lmbench, X-Ray. You should confirm as much of the data as possible using CPUID or an architecture manual.
2. Carefully time and plot the running time for the Numeric recipes matrix multiplication routine discussed in class. Present the data in terms of MFLOPS. Make sure to provide relevent compiler information (type, version, flags). Compare optimized and unoptimized versions. Also measure instructions and L1 data cache misses, and other interesting metrics available through PAPI). Plot the normalized data (i.e. divided by the number operations as in MFLOPS) and compare to peak MFLOPS obtainable on your machine.
3. Experiment with the different loop orders (i.e. ijk, jik, ikj, jik, kij, kji) and the blocked version. You should measure and plot time, instructions, and other interesting metrics available through PAPI, comparing them to the data in part 2.
4. Install ATLAS or MKL on your computing platform and perform the same timings/measurements as you did for numeric recipes and compare. [For extra credit install both and compare]