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:
a) change in mesh size,
b) 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