Difference between revisions of "WRF/WPS"

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== Scaling ==
== Scaling ==
Here a short example (January test case, see [http://www.mmm.ucar.edu/wrf/OnLineTutorial/index.htm WRF tutorial]) of the scaling and wall clock times for different compiler and single and double precision:
Here a short example (January test case, see [http://www.mmm.ucar.edu/wrf/OnLineTutorial/index.htm WRF tutorial]) of the scaling and wall clock times for different compiler and single (SP) and double precision (DP):
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A short visualisation of the times is given below
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|[[File:scaling_wrf_jan.png|center|thumb|300px|Scaling of WRF for different compilers and precisions]]
|[[File:speedup_wrf_jan.png|center|thumb|300px|Speedup of WRF for different compilers and precisions. Note the times are normalized by the time for one core with the same setup.]]
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Revision as of 15:29, 25 January 2013

The software WRF (Weather Research and Forecasting Model) is a numerical mesoscale weather prediction system.


Installation

The get the best performance WRF should be compiled with the Intel compilers and with Intel MPI. For the installation on flow two installation scripts are available:

In both scripts ungrib2 is supported. The usage of the scripts are

    install_wrf_XXXX.sh WRF_RELEASE DIR_TO_TAR_GZ_FILES


Note:

  • The final installation of WRF and WPS will be in the directories WRFV3_v${WRF_RELEASE}_XXXXX and WPS_v${WRF_RELEASE]_XXXXX, respectively
  • The orginal folders WRFV3 and WPS will be removed during the installation process!


SGE script

A basic script to submit WRF to SGE is shown here....


Scaling

Here a short example (January test case, see WRF tutorial) of the scaling and wall clock times for different compiler and single (SP) and double precision (DP):

#Cores GNU compiler [s] Intel compiler [s]
single precision double precision single precision double precision
1 351 292 127 212
2 181 151 62 109
4 98 88 37 62
8 56 51 22 39

A short visualisation of the times is given below

[of WRF for different compilers and precisions] [of WRF for different compilers and precisions. Note the times are normalized by the time for one core with the same setup.]

Known issues

  • The Intel compiler release 12.0.0 produces an bug in the binary ungrib.exe in the WPS-Suite. Due to this bug waves can occurs in the the preprocessed data.
  • The default installation rules of WRF with single precision floating point operations leads to differences in the result of WRF when changing the compiler or the WRF release. Thus WRF should be compiled with double precision floating points.


External links