(RESOLVED) WRF Performance on Multicore processor

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jozamm
Posts: 7
Joined: Sat Nov 07, 2020 3:27 pm

(RESOLVED) WRF Performance on Multicore processor

Post by jozamm » Mon Nov 09, 2020 3:22 pm

Hi all,

I am running WRF on a 6 core machine Core i7 (12 with hyperthreading). I was expecting that when running wrf, the CPU utilization would rise to 80%to 100% per core. However only one core rises up to 100% and the rets of the cores stay at around 10-20%. RAM is not an issue as the machine has 64Gb available the model is using 4Gb of RAM.

Wrf has been compiled with the smpar option. it is running correctly, but I wish to utilize the total power of the PC as the model is refined and add nested domains.

Attached is the namelist.input file

Thanks a lot for the help,

Joseph
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kwerner
Posts: 2248
Joined: Wed Feb 14, 2018 9:21 pm

Re: WRF Performance on Multicore processor

Post by kwerner » Mon Nov 09, 2020 6:21 pm

Hi Joseph,
Have you tried with the distributed-memory option (dmpar) to see if you get better results?
NCAR/MMM

jozamm
Posts: 7
Joined: Sat Nov 07, 2020 3:27 pm

Re: WRF Performance on Multicore processor

Post by jozamm » Mon Nov 09, 2020 6:57 pm

Hi,

Thanks a lot,

I will try to recompile for dmpar.

When I compiled for smpar+dmpar wrf.exe was crashing at the 1st timestep. Should I recompile all libraries according to this webpage https://www2.mmm.ucar.edu/wrf/OnLineTut ... .php#STEP2 instead of downloading them. Ubuntu 20.10 is being used.

Joseph

kwerner
Posts: 2248
Joined: Wed Feb 14, 2018 9:21 pm

Re: WRF Performance on Multicore processor

Post by kwerner » Mon Nov 09, 2020 7:56 pm

If you are able to compile successfully, then the libraries should be fine. We don't recommend using dm+sm, as it can cause many problems, such as the one you're seeing. Let me know how the dmpar compile works for your simulations.
NCAR/MMM

jozamm
Posts: 7
Joined: Sat Nov 07, 2020 3:27 pm

Re: WRF Performance on Multicore processor

Post by jozamm » Wed Nov 11, 2020 8:13 am

Hi,

I recompiled using the dmpar option and all the processors are being utilized.

thanks for all the help,

Joseph

kwerner
Posts: 2248
Joined: Wed Feb 14, 2018 9:21 pm

Re: WRF Performance on Multicore processor

Post by kwerner » Thu Nov 12, 2020 8:20 pm

Great! Thanks for letting me know.
NCAR/MMM

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