Shows it only using 16 threads. I have a dual processor server that I am running boinc on. It has 8 cores/16 threads per processor. Why doesn't it use all 32 threads?

Shows it only using 16 threads. I have a dual processor server that I am running boinc on. It has 8 cores/16 threads per processor. Why doesn't it use all 32 threads?

Looks like the N-body application is unaware of the second cpu. I know other projects run all cores on dual socket hosts like the Universe project. So it isn't a problem with BOINC. Need to have one of the Einstein N-body devs answer your question.

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Why doesn't it use all 32 threads?

What are your CPU usage settings? Does BOINC recognize both CPUs? Check startup messages.

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I have a 12 core 24 thread Ryzen CPU, whenever I ran N-body work units only 1 would run and it would take 16 cores, when that one finished then another would start.

Buggered up the work throughput as most would not be completed before the deadline.

I added an app_config.xml file to make it use only 8 cores and now 3 will happily run and use all threads.

I think 16 is the default, at least for me it was.

In theory if you have 32 threads then it should run 2 work units but not sure about the default nature of the settings if it will then start another WU if one is already running.

Conan

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the app does support > 16 threads, but it doesn't scale well. There is only a 10% improvement 16 vs 32 threads on Ryzen 5950x, so running multiple wu's like 2x16 threads is more efficient.

it would be nice to setup "Max # of CPUs for this project" in the administration like other projects (amicable, primegrid...) have.
app_config.xml is another alternative...

Shows it only using 16 threads. I have a dual processor server that I am running boinc on. It has 8 cores/16 threads per processor. Why doesn't it use all 32 threads?

Are you using an app_config.xml to limit the number of concurrent WUs to 1 or have your boinc preferences set to use less than 100% of the cores?

Looks like the N-body application is unaware of the second cpu. I know other projects run all cores on dual socket hosts like the Universe project. So it isn't a problem with BOINC. Need to have one of the Einstein N-body devs answer your question.

Are you saying universe has an multi-threaded app or just it will use all threads on a multi CPU system with 1 thread per WU?

Are you saying universe has an multi-threaded app or just it will use all threads on a multi CPU system with 1 thread per WU?

No, I was just commenting that other projects can utilize more than a single physical cpu in a host.
Universe tasks are only single threaded for running on a single core. But if you have a two socket host supporting 128 threads per socket, you can have 256 Universe tasks running for example.

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just use app_config.xml

<app_config>
<app>
<name>milkyway_nbody</name>
<max_concurrent>1</max_concurrent>
</app>
<app_version>
<app_name>milkyway_nbody</app_name>
<plan_class>mt</plan_class>
<avg_ncpus>32</avg_ncpus>
<cmdline>-n 32</cmdline>
</app_version>
</app_config>