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Captiosus

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Message 66814 - Posted: 26 Nov 2017, 21:38:17 UTC

I was wondering, is there a way to split MT N-Body units so that instead of say, 1 unit taking up all 12 threads, i can have 2 units using 6 threads each?
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mmonnin

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Message 66818 - Posted: 29 Nov 2017, 19:34:18 UTC - in response to Message 66814.  

I was wondering, is there a way to split MT N-Body units so that instead of say, 1 unit taking up all 12 threads, i can have 2 units using 6 threads each?


Yes you can use an app config with ncpus option to make it run on however many threads you like.

Here is an example from cosmology FAQ. Just have to update the app_name and plan_class. Event log will tell you the correct app name and plan class is in the ( ) of the task, usually something like MT, CUDA, or OpenCL for GPUs.
http://www.cosmologyathome.org/faq.php

<app_config>
    <app>
        <name>camb_boinc2docker</name>
        <max_concurrent>1</max_concurrent>
    </app>
    <app_version>
        <app_name>camb_boinc2docker</app_name>
        <plan_class>vbox64_mt</plan_class>
        <avg_ncpus>2</avg_ncpus>
    </app_version>
</app_config>
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Captiosus

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Message 66821 - Posted: 30 Nov 2017, 14:58:14 UTC - in response to Message 66818.  

Cheers! Took a little bit to get it right, but i got it and now hopefully it will help in improving CPU utilization a bit.
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mmonnin

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Message 66822 - Posted: 30 Nov 2017, 20:31:57 UTC

Good to here.

And holy crap, I copied in the text from the website and didn't notice all of the other junk. Code tags not only do not keep formatting but I guess don't keep text as is like it should. For a future reference here's the correct text from Cosmo FAQ.

<app_config>
<app>
<name>camb_boinc2docker</name>
<max_concurrent>1</max_concurrent>
</app>
<app_version>
<app_name>camb_boinc2docker</app_name>
<plan_class>vbox64_mt</plan_class>
<avg_ncpus>2</avg_ncpus>
</app_version>
</app_config>
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Captiosus

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Message 66825 - Posted: 1 Dec 2017, 2:30:22 UTC

Ha yeah, I probably should have mentioned that your initial copy over from Cosmology@home completely mangled the code.
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Message boards : Number crunching : Splitting MT N-body?

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