Basic HTML version of Foils prepared October 1995

Foil 6 Load Imbalance arises after i iterations over columns:

From Intro HPF September 27, 1995 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Tom Haupt and Nancy McCracken


Many processors are completely idle, while the last column of processors still has the same running time.
Better Decomposition is Block by Rows: After iterating over i columns, each processor is still working on n-i+1 row elements. Better load balance and better running time, as time of longest running processor is reduced each iteration.



© on Tue Oct 7 1997