Sunflower not using whole CPU power

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Message 10748 - Posted: 12 Feb 2011, 21:44:35 UTC

Hi,

It seems that sunflower WUs is using multiple cores in one WU. This is nice. Problem is that in begining of task there is some task, which use only one (or two) cores. That means, that not whole time is used whole CPU power. Load of my machine with 8 cores is just around 5 (not 9) like usual when boinc running.

Can be done anything with this? Perhaps limit WU to just 2 or 4 cores. Is it possible to use variable number of cores by one WU? (I crunch this tasks in around 15 minutes)

PS: Is there any performance comparison in OS used? Just some select to find same processors on same WU, with different OS and make some observations.

PPS: What format is used for output image?
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Message 10779 - Posted: 18 Feb 2011, 18:44:49 UTC - in response to Message 10748.  

Newer version of linux 64 bit sunflower is somehow different in cpu ussage...

Just one suggestion. Try to add cpu usage monitor to cruncher app. For example it could compute average cpu usage for all subtasks. It could improve percentage calculation (ie, you will know, that initialization task uses only two threads and takes 5% of whole wu on 8 core machine)...

PS: now sunflover wu has 89.2% done and using just 77% of cpu (8 cores).
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Message 10783 - Posted: 18 Feb 2011, 20:07:04 UTC - in response to Message 10779.  

Another hint, I would like to set up in my burp preferences that one wu should render for example 0.5 frame per core used. It will than on 8 core system render 4 frames in one wu. This will lower wu startup overhead and can save some energy. Finally it would also make duration of wu adjustable per user, like in rosetta project.

PS: Somewhere was mentioned, that only seti@home project is using optimized binaries. It is not true now. Minimally einstein project is distributing sse/sse2 optimized binaries. Does someone tested what difference it makes and if the result is same?
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Message 10790 - Posted: 19 Feb 2011, 20:47:23 UTC
Last modified: 19 Feb 2011, 20:48:12 UTC

Is it possible to use variable number of cores by one WU?

I've been thinking the same; or rather that it would be smart if the WU could somehow inform BOINC that it was currently only using 1-2 cores and then later 8 and so on. That way BOINC can run other tasks simultaneously alongside the current workunit. I'm not sure this ever made it into the BOINC API, but it would certainly be one of the things to look at as a potential optimization in the future.
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Message boards : Number crunching : Sunflower not using whole CPU power