Limit on cores for WRF

[llsalazardom]

Does the WRF source code have any limits on the number of cores that can be used? We have read an article where they explain the following:

''
Minor modifications were made to the WRF source code in order to facilitate this study. In order to run WRF on 64K cores, WRF source had to be modified as it is limited to 10,000 MPI processes by default.
''

 

[kwerner]

I wasn't aware of any limitation, but I did a search through the code, and in external/RSL_LITE/rsl_lite.h, there is a line

#define RSL_MAXPROC 100001

which is likely the limit they are referring to. I assume that could be modified, but I'm not sure if it would cause other issues in other parts of the code to do so.

You're probably already aware of the information in Choosing an Appropriate Number of Processors, but just in case you're interested in guidance, you can read the recommendations in that FAQ.

 

[llsalazardom]

Thank you very much @kwerner