CPU time loss by finishing tasks


Message boards : Number crunching : CPU time loss by finishing tasks

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Thruuk

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Message 8970 - Posted: 9 May 2025, 8:11:07 UTC
Hello,

I have an problem while running asteroids@home:

When an task from asteroids finished and is uploaded, boinc/the system becomes busy ("cpu is busy") and stop running all tasks for around 20 seconds.

My cpu has 24 threads and an asteroids wu is running around 40 minutes.
When only asteroids is running, approximatly every 100 seconds a wu should end and then the system paused for around 20 seconds.
So the system losses around 15 % of cpu time beause of this behavior.

In other projects like Einstein or MilkyWay i couldn't see this effect. And because of longer runtime from wu's the effect wouldn't be so big.

Did somebody know what to do against this?
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Lamberto Vitali

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Message 8972 - Posted: 9 May 2025, 8:23:34 UTC - in response to Message 8970.  
How much is busy? 1 core? All the cores? I see a delay whenever boinc rearranges things of 30 seconds on a slow computer and 5 seconds on a fast one, but it's only one core. This shows in windows task manager as Boinc manager using a whole core. I cannot interact with Boinc during this time, but the other tasks continue on the rest of the cores.
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Thruuk

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Message 8973 - Posted: 9 May 2025, 8:31:22 UTC

Last modified: 9 May 2025, 8:32:58 UTC
The whole system is going down.

I take a look in the windows task manager and when the wu is finished and uploaded, the cpu and also gpu usage of the computer go down to nearly 0 % for around 20 seconds.

The computer is a Ryzen 9 7900 12 core. This is not a slow one ...
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Lamberto Vitali

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Message 8988 - Posted: 28 May 2025, 14:49:39 UTC - in response to Message 8973.  
Are you running Asteroids on GPU, CPU, or both? Are you using other projects at the same time?
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benhines

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Message 8989 - Posted: 28 May 2025, 20:03:21 UTC
Do you have a restriction on Boinc processing "While processor usage is less than" set? In that case, it might be the overhead of the send/update on top of the task work is just tripping it out, and it waits for it to recover
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Thruuk

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Message 8994 - Posted: 6 Jun 2025, 8:44:54 UTC
I am only running CPU Tasks.
Other projects runnig are Milkyway and Einstein.

And yes, I have the restriction, that boinc should stop, wenn CPU usage is higher than 50 %.
But Boinc Manager schould not need more than 50 % of cpu usage! This is a Ryzen 9700 with 12 cores/24 threads ...
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Lamberto Vitali

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Message 8995 - Posted: 6 Jun 2025, 18:26:10 UTC
I don't trust Boinc settings, crank it up to 100% and see what happens.

The setting I use to let me use the computer nicely for general use is to turn down the number of cores (CPUs they call them) used by Boinc to 90%.

If you play games or anything else needing a lot of computer power, you can give Boinc an exception to stop when that program is running.
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Message boards : Number crunching : CPU time loss by finishing tasks