Comparison of execution times. The blue line at the bottom indicates the computation time for 3D median filtering as a function of the number of processors used. As the number of processors increased from 32 to 1024, the computation time decreased from 606 to 18.8 seconds. A logarithmic scale is used for both axes. The red line on the top shows the computation time for the same task running on a 2 GHz Intel processor inside an IBM Thinkpad machine. Clearly, several orders of magnitude speedup can be achieved in a multiprocessor environment.