# OpenMC Plotter not using the cores specified

**URL:** <https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855>\
**Category:** User Support\
**Created:** [October 2, 2024, 12:08am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855 "2024-10-02T00:08:47Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![thallam](https://avatars.discourse-cdn.com/v4/letter/t/71c47a/32.png) [@thallam](https://openmc.discourse.group/u/thallam)\
**Post date:** [October 2, 2024, 12:08am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855/1 "2024-10-02T00:08:47Z")

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Hello,

Hopefully one of you can help me. I am using the OpenMC plotter and for some reason when i use command openmc-plotter -s 24 it doesn’t use all 24 of my cores. When i just use the command openmc-plotter it looks like it runs slower and only uses one core. Anyone know why this is the case??

Thanks

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**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [October 2, 2024, 12:52am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855/2 "2024-10-02T00:52:14Z")

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The `-s` command line argument affects the number of threads that are used on internal calls to OpenMC when it is generating a plot (i.e., every time you change the plot view). Those calls will use the number of threads that you specify, but the GUI window itself does not require multiple threads.

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<div class="post-metadata">

**Author:** ![thallam](https://avatars.discourse-cdn.com/v4/letter/t/71c47a/32.png) [@thallam](https://openmc.discourse.group/u/thallam)\
**Post date:** [October 2, 2024, 1:09am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855/3 "2024-10-02T01:09:05Z")

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It takes forever to load the gui

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**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [October 2, 2024, 1:22am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855/4 "2024-10-02T01:22:08Z")

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Try changing the default resolution to see if that helps: `openmc-plotter -r 10`

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<div class="post-metadata">

**Author:** ![thallam](https://avatars.discourse-cdn.com/v4/letter/t/71c47a/32.png) [@thallam](https://openmc.discourse.group/u/thallam)\
**Post date:** [October 2, 2024, 1:24am UTC](https://openmc.discourse.group/t/openmc-plotter-not-using-the-cores-specified/4855/5 "2024-10-02T01:24:40Z")

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![17278322514066059462943611074313](https://global.discourse-cdn.com/free1/uploads/openmc/original/2X/b/b6313a4a5cf78708713cd390658a08fb515be067.jpeg)

Doesn’t Look like that is an option