CSCI 3366 (Introduction to Parallel and Distributed Processing), Spring 2008:
Homework 3 Solution

Solution

(Caveat: Plots are based on data collected when I first developed these programs, in Fall 2006. To the extent that I collected data this year, however, results were comparable.)

Sequential program

• game-of-life.c.

Parallel programs and plots

• OpenMP program game-of-life-openmp.c.

• MPI program game-of-life-mpi.c. (I used a slightly different version to collect timing information: game-of-life-mpi-old.c. The difference is that this older version exchanges data between processes in a way that can block if messages are too big. Apparently that wasn't a problem when I initially collected performance data, for the board sizes I used, but it was when I repeated some experiments this year. It's sloppy coding anyway.)

• Plot of execution time versus number of UEs (total time, including initialization and printing final board) plot of execution time versus number of UEs (time for computation only). (The assignment asked for separate plots, but I thought it might be more interesting to do combined plots, to compare the different programming environments. The plots also show sequential time divided by number of UEs -- ``perfect'' parallel time. As in Homework 2, I used gnuplot to produce these plots, with input such as this.)