[Wrf-users] Execution Time Difference of ARW core versus NMM core

[mmacleod]

Good morning Folks.

We are setting up and testing the WRF cores for our company.  We have 
compiled both the ARW core and the NMM core on a small Dell dual core 
machine while we await the "big production system".

It is our understanding that the NMM core is about three times faster 
than the ARW core for the same configuration.

To test this we use the NAM 12 km in hourly outputs as the "driving model".

We set a 12 km 30 X 30 grid with 28 vertical levels.   We run the model 
to 6 hours. 

The OS is Ubuntu 8.4

We use the date  >  RUNTIME.LOG  command before the start of the wrf.exe 
module and the date >> RUNTIME.LOG to get the start and stop times.

Here is the results of the 6 hour runs:


NNM - 12 KM - 30 X 30 grid 28 levels  - 6 Hours

Thu Nov  6 19:55:49 GMT 2008
Thu Nov  6 20:04:03 GMT 2008


6 hr Run Time = 8 min 15 seconds

Run Time per hour = 1 min 22 seconds


ARW - 12 KM - 30 X 30 grid 28 levels  - 6 Hours

Thu Nov  6 20:34:00 GMT 2008
Thu Nov  6 20:35:38 GMT 2008


6 hr Run Time = 1 min 38 seconds

Run Time per hour = 27 seconds


This indicates that the NMM is three times slower than the ARW. 

Is this true in general?  If not what might be the cause of of our result?

Thanks in advance for your help.

Mac  

-- 
M.A. (Mac) MacLeod
President and General Manager
Scotia Weather Services Inc
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