Variation of GuC-Factor (situation at time t=0.5)
The Grid-Unit-Coarsening-Factor defines the minimal size of a unit of the base grid that is used for partitioning. For instance, a GuC-Factor =4 means, that units of 4x4 base cells are used. Higher GuC-Factors simplify partitioning, but usually lead to load-imbalance. If a relatively fine base grid is used, larger GuC-Factors can speed up the partitioner drastically (see example
Backward facing step). The default value is 2.
Workload for different GuC-factors - Distribution with Hilbert space filling curve. 4 computing nodes are used.
GuC-Factor | P1 | P2 | P3 | P4 |
2 | 0.932 | 1.062 | 1.044 | 0.962 |
4 | 0.914 | 1.097 | 1.057 | 0.931 |
8 | 0.778 | 1.433 | 0.843 | 0.946 |
GuC-Factor=2
GuC-Factor=4
GuC-Factor=8
Benchmark
Task | GuC-Factor=2 | GuC-Factor=4 | GuC-Factor=8 |
s | % | s | % | s | % |
Integration | 2246 | 67.2 | 2182 | 65.8 | 2163 | 60.2 |
Flux correction | 180 | 5.4 | 201 | 6.1 | 275 | 7.6 |
Boundary setting | 315 | 9.4 | 386 | 11.6 | 636 | 17.7 |
Recomposition | 496 | 14.9 | 453 | 13.7 | 426 | 11.8 |
Clustering | 37 | 1.1 | 34 | 1.0 | 32 | 0.9 |
Misc. | 56 | 2.0 | 52 | 1.9 | 52 | 1.7 |
Total / Parallel Efficiency | 3329 | 85.1 | 3307 | 85.7 | 3733 | 75.9 |
P=4
<--- Problem description
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RalfDeiterding - 04 Dec 2004