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Standard Performance Evaluation Corporation

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173.applu
SPEC CPU2000 Benchmark Description File


Benchmark Name

APPLU


Benchmark Author

Sisira Weeratunga


Benchmark Program General Category

Computational Fluid Dynamics and Computational Physics


Benchmark Description

Solution of five coupled nonlinear PDE's, on a 3-dimensional logically structured grid, using an implicit psuedo-time marching scheme, based on two-factor approximate factorization of the sparse Jacobian matrix. This scheme is functionally equivalent to a nonlinear block SSOR iterative scheme with lexicographic ordering. Spatial discretization of the differential operators are based on second-order accurate finite volume scheme. Insists on the strict lexicographic ordering during the solution of the regular sparse lower and upper triangular matrices. As a result, the degree of exploitable parallelism during this phase is limited to O(N**2) as opposed to O(N**3) in other phases and it's spatial distribution is non-homogenous. This fact also creates challenges during the loop re-ordering to enhance the cache locality.


Input Description

There are two approaches to control the memory and run-time requirements of the benchmark:

  1. change in mesh size,
  2. change in number of time steps taken.

For a fixed mesh size, run-time varies linearly with the number of time steps taken. Currently, input decks are available for several different pairs of mesh cubic sizes and the number of time steps taken. Realistic workloads would involve meshes that contain in excess of 125,000 mesh points (i.e., 51X51X51 grid) and at least several hundred time steps.


Output Description

The program is capable of automatically verifying whether a given run conforms to the specification of the benchmark by using internally stored reference solutions. However, these reference solutions are available only for a fixed number of mesh size/time steps pairs. If the input data does not correspond to any of the internally stored reference solutions, the verification test is not performed. Otherwise, the output indicates whether or not the run was successfull in meeting the requirements of the verifications tests. To conform to the specification of the benchmark, a run should successfully pass all three verification tests. Failure in any one or more tests indicates non-conformance with the specifications.


Programming Language

Fortran 77


Known portability issues

None


Reference

E. Barszcz, R. Fatoohi, V. Venkatkrishnan and S. Weeratunga "Solution of Regular Sparse Triangular Systems on Vector and Distributed-Memory Multiprocessors", Rept. No: RNR-93-007, NASA Ames Research Center, 1993
http://www.nas.nasa.gov/Pubs/TechReports/ebarszcz/RNR-93-007/RNR-93-007.html

Last Updated: 14 December 1999