Параллельные вычисления в ИММ УрО РАН
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Next: Performance Bottlenecks in the Up: Performance Evaluation Previous: Determine Whether Reasonable Performance
Identify Performance BottlenecksThe formulas mentioned in section 5.3.3, in addition to providing an estimate of performance, can help one identify whether the performance is limited by computation, by the number of messages, or by the volume of communication. Even if the estimate is far from correct, the user may get some information about the performance bottleneck by studying the computation and communication estimates provided by those formulas. Comparing the execution times of a problem of size N and one of size N/2 may also provide insight into the performance of the ScaLAPACK routine being used. Let and be the time required for a problem of size N and size N/2, respectively, on P processors.
Susan Blackford Tue May 13 09:21:01 EDT 1997 |