Message boards : Number crunching : Issue with LHC@home preferences
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Crystal Pellet
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Message 40500 - Posted: 18 Nov 2019, 11:59:31 UTC

I selected only Theory application. I had set 2 for Max # of jobs for this application and for Max # of CPUs for this project 1.

When asking new CPU-work I don't get 2 tasks, but when I set Max # of CPUs to 2, I get a second task.
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Harri Liljeroos
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Message 40501 - Posted: 18 Nov 2019, 12:05:33 UTC - in response to Message 40500.  
Last modified: 18 Nov 2019, 12:06:01 UTC

That seems to be same as for Atlas tasks. The Max number of CPUs limits the Max number of tasks you receive from the server. I have never understood why.
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Jim1348

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Message 40503 - Posted: 18 Nov 2019, 13:58:44 UTC - in response to Message 40501.  

I have never understood why.

You can read the official explanation:
https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=4686&postid=35258#35258

You can deal with it using an app_config.xml if you are using native ATLAS. (I don't think it works with the VBox version.)
https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=4686&postid=35121

I expect that the LHC admins would like to fix it too, but it is apparently out of their hands.
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Aurum
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Message 40506 - Posted: 18 Nov 2019, 15:49:27 UTC - in response to Message 40503.  

That explains the bizarre behavior of ATLAS but not nTheory.
#WUs = Unlimited
#CPU = 1, 2, 3, 4, 5, 6, 7, 8
WU max: 2, 4, 6, 8, 10, 10, 10, 10
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computezrmle
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Message 40508 - Posted: 18 Nov 2019, 16:27:12 UTC

Isn't it time to ignore the accountants and get rid of this misinterpretation of #CPUs?
Experienced users find a couple of workarounds to get their multi CPU hosts saturated.
Just set up multiple clients on the same box, each with only a few "CPUs".


The preferences should work as an average volunteer expects them to work:
Max # jobs -> sets the max number of tasks a BOINC client can hold in it's buffer
Max # CPUs -> sets the number of cores/threads a task/VM will use


No "special" interpretation for project X and a different one for project Y.
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Message boards : Number crunching : Issue with LHC@home preferences


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