Intel i5 2400 cpu's speed wobbles up and down (according to task manager) when running gpu task. Fix?

Message boards : Number crunching : Intel i5 2400 cpu's speed wobbles up and down (according to task manager) when running gpu task. Fix?
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Profile Tom Miller
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Message 1871037 - Posted: 4 Jun 2017, 2:59:29 UTC

Hi,
When I run the Boinc/Seti task without any seti gpu processing all four cores report 25 (%?). Now when I run 1 or more gpu tasks, the 4 cores start changing amounts. To say 12, 13, 25, 25 The gpu task is currently reporting 25.

If I run this without -cpu_lock there is a nearly constant cycle between 12 and 25 on all cores.

If I run 3 cpu cores and 1 core dedicated to the gpu, without -cpu_lock, 2 cores stay at 25 and 1 core varies from 12 to 25.

So since my goal is "maximum production" of the over all system is there anything I can do that might smooth out the cpu variation? Which might speed up cpu production without slowing the gpu production much?

Thank you,
Tom
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Grant (SSSF)
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Message 1871038 - Posted: 4 Jun 2017, 3:07:32 UTC - in response to Message 1871037.  

So since my goal is "maximum production" of the over all system is there anything I can do that might smooth out the cpu variation?

The variation means you are getting maximum production.
Personally I use app_config to reserve 1 CPU core per GPU WU and let it do it's thing. The GPU is never waiting on a CPU thread, and the CPU threads crunching CPU WUs can vary their load as necessary.
Grant
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Profile Raistmer
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Message 1871067 - Posted: 4 Jun 2017, 9:34:40 UTC

Maximum production is quite complicated thing actually.
To maximize production of device one should carefully account for both speedup _and_slowdown of device's different parts.
And cause RAC can vary just because of different work supplied over time such accounting becomes increasely difficult being done online.

Look for few case studies of this problem:
http://lunatics.kwsn.info/index.php/topic,1735.0.html

And here is one possible way how to make it online:
http://lunatics.kwsn.info/index.php/topic,1806.0.html (next step will be to apply statistics to collected data and represent binned, averaged graphs with standard error), but when differencies big enough human eye is qute good for doing this processing in analog way just by looking what graph going higher/lower overall.
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Profile Wiggo "Socialist"
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Message 1871070 - Posted: 4 Jun 2017, 10:24:11 UTC

If you have your preferences set to use 100% of your processors and use an app_config.xml like this,
<app_config>
	<app>
	<name>setiathome_v8</name>
	<gpu_versions>
		<gpu_usage>1</gpu_usage>
		<cpu_usage>1</cpu_usage>
	</gpu_versions>
	</app>

	<app>
	<name>astropulse_v7</name>
	<gpu_versions>
		<gpu_usage>1</gpu_usage>
		<cpu_usage>1</cpu_usage>
	</gpu_versions>
	</app>
</app_config>

you should get near on a constant 100% CPU load with 1 core dedicated to the GPU (that's 3 CPU tasks and 1 GPU task).

Cheers.
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Message boards : Number crunching : Intel i5 2400 cpu's speed wobbles up and down (according to task manager) when running gpu task. Fix?


 
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