[Wrf-users] What is a reasonable speed for WRF / how to increase it?

[Carlos Ross]

Hi Yiapoing,

The core is the hardware, the thread is like the number of process executed
by the core, each of your cores can process two threads, so you don't have
12 cores per processor you have 6 (
http://ark.intel.com/products/47922/Intel-Xeon-Processor-X5650-12M-Cache-2_66-GHz-6_40-GTs-Intel-QPI
).
so instead you run wrf with mpirun -np 44 you should do it with mpirun -np
22.
There is also a way of binding to core, so it doesn't keep jumping to other
cores (I don't know too much about this). I have it like this: mpirun -np
16 --map-by socket:PE=2 wrf.exe
I hope that works for you.

2016-09-02 19:33 GMT-03:00 Wang, Yaoping <wang.3866 at buckeyemail.osu.edu>:

> Hi,
>
>
> Could you explain more about the "using 2 process in one core" and how to
> find out/address it? I am not very familiar with the technical aspect of
> supercomputing. I thought one core in supercomputing means one CPU, but
> did you mean that each CPU is further made up of multiple "little-cores"
> themselves, or 2 cores can be on the same CPU?
>
>
> I am compiling MPI using the intel compiler. But here is another problem.
> OpenMP does not work at all on my system. The compiler finishes
> successfully, but then, when I run "./real.exe", it segfaults without even
> creating an rsl file. I tried using "./configure -d", and updating my WRF
> version from 3.8 to 3.8.1, but the segfault was the same. Do you know what
> else I might do? I attached my "configure.wrf" and "configure.wps" files.
>
>
> I also tested 44 cores with no luck. Increasing the number of nodes from 4
> to 6 only increased the throughput marginally.
>
>
> Thank you,
>
> Yaoping
> ------------------------------
> *From:* wrf-users-bounces at ucar.edu <wrf-users-bounces at ucar.edu> on behalf
> of Mike Dvorak <mike at sailtactics.com>
> *Sent:* Thursday, September 1, 2016 5:05:28 PM
> *To:* wrf-users at ucar.edu
> *Subject:* Re: [Wrf-users] What is a reasonable speed for WRF / how to
> increase it?
>
> Hi Yaoping,
>
> What parallelization option did you compile WRF with (e.g. MPI only)?
> Also, I've found the Intel compilers to be 3 times faster than the GNU
> compilers on some WRF configurations (unfortunately). What compiler did you
> use?
>
> You may also want to experiment using less than the number of total cores
> on the machine. For example, you could try using 44 cores instead of 48. I
> think WRF EMS is set to do this by default. I've verified on some of my
> multi-core machines that this does indeed reduce the runtime.
>
> Cheers,
> Mike
>
>
> On 09/01/2016 03:15 PM, Carlos Ross wrote:
>
> I think it should be faster, Xeon x5650 CPUs are 6 cores and 12 threads,
> so you maybe using 2 process in one core and that is slowing it down.
>
> 2016-08-31 18:36 GMT-03:00 Wang, Yaoping <wang.3866 at buckeyemail.osu.edu>:
>
>> Hi All,
>>
>>
>> I am running WRF on a ~6km resolution, 91 x 121 domain in the eastern
>> United States. I am using an adaptive time step which makes it mostly 72
>> sec increments. There are 34 vertical levels. I use 4 x 12 cores on
>> a Intel Xeon x5650 CPUs machine. The throughput is about 1.2 hour wall
>> time per 24 hours model time.
>>
>>
>> Is this a reasonable speed? I found some information here (
>> http://www.ecmwf.int/sites/default/files/elibrary/2014/1366
>> 2-performance-analysis-operational-implementaion-wrf.pdf) and after
>> considering the domain difference, my run still seems a touch slow. And is
>> there anyway I could figure how to make the model run faster?
>>
>>
>> Thank you,
>>
>> Yaoping Wang
>>
>> _______________________________________________
>> Wrf-users mailing list
>> Wrf-users at ucar.edu
>> http://mailman.ucar.edu/mailman/listinfo/wrf-users
>>
>>
>
>
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>
> --
> [image: Sail Tactics logo]
> Mike Dvorak, PhD
> Founder
> Sail Tactics, LLC
> Corpus Christi, TX
> +1 650-454-5243
> http://sailtactics.com
>
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