# \[openmc-users\] Sample Simulations?

**URL:** <https://openmc.discourse.group/t/openmc-users-sample-simulations/360>\
**Category:** User Support\
**Created:** [October 8, 2018, 1:27pm UTC](https://openmc.discourse.group/t/openmc-users-sample-simulations/360 "2018-10-08T13:27:21Z")\
**Posts on this page:** 2\
**Page:** 1

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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 8, 2018, 1:27pm UTC](https://openmc.discourse.group/t/openmc-users-sample-simulations/360/1 "2018-10-08T13:27:21Z")

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Hi Blake,

You can specify how many particles you want to run in the settings.xml file. Running more particles will result in better statistics (i.e., lower standard deviation). The run time should scale directly proportional to the number of particles, so if you increase the number of particles by a factor of 10, your simulation should run 10 times longer. For a k-eigenvalue problem, particles are grouped into batches, so you can also change the number of batches. I’d recommend reading the section in our user’s manual on simulation settings and particular the [number of particles](https://openmc.readthedocs.io/en/stable/usersguide/settings.html#number-of-particles).

Best regards,  
Paul

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**Author:** ![Blake\_Ehrenbeck](https://avatars.discourse-cdn.com/v4/letter/b/ed8c4c/32.png) [@Blake\_Ehrenbeck](https://openmc.discourse.group/u/Blake_Ehrenbeck)\
**Post date:** [October 22, 2018, 5:09pm UTC](https://openmc.discourse.group/t/openmc-users-sample-simulations/360/2 "2018-10-22T17:09:37Z")

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Thank You, I’ve adjusted the number of particles and am getting longer runs!