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nairb

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Message 74188 - Posted: 15 Sep 2022, 22:12:35 UTC

On both the win10 & linux machines the nbody tasks only seem to use about 90% of the cpu. Both have the cpu usage set to 100% on the computing prefs. Other projects use the full cpu (100%).

Is this typical of the nbody process??

Ta
Nairb
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diegobo

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Message 74714 - Posted: 29 Nov 2022, 14:12:24 UTC - in response to Message 74188.  

same here, n-body (12 CPUs) using 82%...
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Message 74715 - Posted: 29 Nov 2022, 14:47:59 UTC
Last modified: 29 Nov 2022, 14:50:42 UTC

IIRC the solution is to run more than one task concurrently with app_config.xml file.

<app_config>
 <app>
  <name>milkyway_nbody</name>
  <max_concurrent>3</max_concurrent>
 </app>
 <app_version>
  <app_name>milkyway_nbody</app_name>
  <plan_class>mt</plan_class>
  <avg_ncpus>4.0</avg_ncpus>
  <cmdline>--nthreads 4</cmdline>
 </app_version>
</app_config>

This will run 3 n-Body tasks with each 4 threads on a 12 core CPU. If that isn't enough, you can try "--nthreads 5" without changing anything else, but you'll have to see, if that really improves the throughput. Don't do it, if the CPU also needs to feed a GPU.
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diegobo

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Message 74716 - Posted: 29 Nov 2022, 18:38:06 UTC - in response to Message 74715.  

thanksss, 95% now
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Skip Da Shu
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Message 75165 - Posted: 19 Mar 2023, 17:27:00 UTC - in response to Message 74715.  

IIRC the solution is to run more than one task concurrently with app_config.xml file.

<app_config>
 <app>
  <name>milkyway_nbody</name>
  <max_concurrent>3</max_concurrent>
 </app>
 <app_version>
  <app_name>milkyway_nbody</app_name>
  <plan_class>mt</plan_class>
  <avg_ncpus>4.0</avg_ncpus>
  <cmdline>--nthreads 4</cmdline>
 </app_version>
</app_config>

This will run 3 n-Body tasks with each 4 threads on a 12 core CPU. If that isn't enough, you can try "--nthreads 5" without changing anything else, but you'll have to see, if that really improves the throughput. Don't do it, if the CPU also needs to feed a GPU.


Can I use the nthreads option to stop getting CPU WUs that require 15 threads? Hoping so as I copied your app_config into boinc-client/projects/milkyway.cs.rpi.edu_milkyway folder... so pending a download request to see.

Yeehaw... worked! Now I can tweak it.

Thanx much, Skip
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Message boards : Number crunching : cpu usage

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