357.bt331
SPEC OMP2012 Benchmark Description File
Benchmark Name
357.bt331
Benchmark Author
R. Van der Wijngaart
T. Harris
M. Yarrow
H. Jin
Benchmark Program General Category
Computational Fluid Dynamics
Benchmark Description
BT is a simulated CFD application that uses an implicit algorithm to
solve 3dimensional (3D) compressible NavierStokes equations. The
finite differences solution to the problem is based on an Alternating
Direction Implicit (ADI) approximate factorization that decouples the
x, y and z dimensions. The resulting systems are BlockTridiagonal of
5x5 blocks and are solved sequentially along each dimension.
Input Description
There are two approaches to control the memory and runtime requirements
of the benchmark:

change in mesh size,

change in number of time steps taken.
For a fixed mesh size, runtime 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.
For the SPEC benchmark, the reference data set uses a grid of
408x408x408 with 130 iterations and a time step of 0.00002.
The train data set uses a grid of 102x102x102 with 200 iterations and
a time step of 0.0003. The test data set uses a grid of
64x64x64 with 200 iterations and a time step of 0.0008.
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
nonconformance with the specifications.
For SPEC, the solution is output for comparison to a set of
reference values.
Programming Language
Fortran
Known portability issues
None
Reference
H. Jin, M.Frumkin and J.Yan, "The OpenMP Implementation of
NAS Parallel Benchmarks and Its Performance",
Rept. No: NAS Technical Report NAS99011 October 1999
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Last Updated: 15 July 2010