WRF Acceleration Options

Dear WRF community，

I am trying to accelerate WRF simulation since processing long-term climate simulation. The factors which might influence the speed are listed for my knowledge:

• Hardware (CPU)
• MPI: serial/smpar/dmpar/
• Compiler
--PGI/intel fortran/GNU
--optimization
• Namelist
--time_Step
--physical options

My questions are:
(1) Someone argues that using Intel/PGI as compiler would be faster that GNU, is it true?
-Intel/PGI compiler + dmpar would be the best choice? Are they free and mpi supported?
-what is the optimization options when compiling?
(2) How to optimize the namelist.input setting for my purpose?
-For example, the time_step is necessary to be 180, and history_interval to be 180s, 60s for domain1&domain2, respectively? (attached namelist.input.01 only for 1 year)
-dfi would be necessary for a long-term climate simulation?

Is there any references for this topic? Thanks in advance.

Siliang

Hi Siliang,

1) Typically Intel and PGI run WRF simulations faster, but they take longer to compile the code, so if you plan to modify a lot of code and need to compile many times, you may not want a compiler that builds slowly; however, if you only plan to compile once and run large runs (as you've indicated), then Intel or PGI may be a better choice. Unfortunately those 2 compilers are not free and you must pay for a license to install them. You can take a look at this talk given at our WRF tutorial for a bit more information on compiling options:
http://www2.mmm.ucar.edu/wrf/users/tutorial/201901/werner_compiling.pdf

2) For namelist best practices, take a look at these 2 web pages:
http://www2.mmm.ucar.edu/wrf/users/namelist_best_prac_wps.html
http://www2.mmm.ucar.edu/wrf/users/namelist_best_prac_wrf.html


Kelly