481.wrf
SPEC CPU2006 Benchmark Description

Benchmark Name

481.wrf

Benchmark Author

National Center for Atmospheric Research (NCAR) in collaboration with multiple government agencies, universities, and others.

Benchmark Program General Category

Weather Forecasting

Benchmark Description

481.wrf is based on the Weather Research and Forecasting (WRF) Model, which is a next-generation mesocale numerical weather prediction system designed to serve both operational forecasting and atmospheric research needs.

WRF features multiple dynamical cores, a 3-dimensional variational (3DVAR) data assimilation system, and a software architecture allowing for computational parallelism and system extensibility. The parallel portions of the code have been turned off for SPEC CPU2006 as the interest here is in single processor performance.

WRF is suitable for a broad spectrum of applications across scales ranging from meters to thousands of kilometers.

WRF version 2.0.2 is used in the benchmark version, 481.wrf.

Input Description

The WRF Standard Initialization (SI) software is used to create the data sets. The June 2001 SI data archived at NCAR is used as data sets. The data is 10 km from 1200 UTC June 11 - 1200 UTC Jun 12 2001 at 3 h interval.

Output Description

The temperature at a certain grid point is printed for every time step and validated.

Programming Language

Fortran 90 and C

Known portability issues

481.wrf requires the netCDF library for I/O. netCDF is packaged as part of the source, but may need to be configured for your system. SPEC_CPU portability options are provided.

481.wrf uses unformatted I/O to read its data files. By default, files with 4-byte headers will be read. If your system requires 8-byte headers, please set

  wrf_data_header_size = 8

in the 481.wrf section of your config file.

Portability issues fixed subsequent to the release of SPEC CPU2006 V1.0

• New with CPU2006 V1.1, added new portability flag -DSPEC_CPU_NEED_IO_H to include the header file io.h on Windows. Previously, io.h was only included if _MSC_VER was defined by the compiler.

• New with CPU2006 V1.1, fixed a Fortran 90 standards violation where two associated dummy arguments were defined during the execution of a subprogram. Note that this update used the same fix as WRF version 2.2. (481.wrf is based on WRF version 2.1).

  In a bit more detail: There is a subroutine in module_bl_ysu.F90 that is called in violation of the Fortran standard about variable overlapping. The routine tridin has three variables (cu,r1,r2) that are passed in the same parameters as (au,a1,a2) in both calls. The new code has fixed this problem by making copies of the read-only versions of the duplicated parameters before the call.

References

• http://www.wrf-model.org/index.php

Last updated: $Date: 2008-04-12 08:31:17 -0400 (Sat, 12 Apr 2008) $