# Running with more cpus

**URL:** <https://calculix.discourse.group/t/running-with-more-cpus/648>\
**Category:** Uncategorized\
**Created:** [June 28, 2021, 3:02pm UTC](https://calculix.discourse.group/t/running-with-more-cpus/648 "2021-06-28T15:02:21Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![FredXG](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@FredXG](https://calculix.discourse.group/u/FredXG)\
**Post date:** [June 28, 2021, 3:02pm UTC](https://calculix.discourse.group/t/running-with-more-cpus/648/1 "2021-06-28T15:02:21Z")

</div>

Hello Everyone,  
I´m pretty fresh about Calculix. I want to know whether there´s a way to run a simulation with more CPUS in Calculix? Thanks a lot!

Current Info:  
Using up to 1 cpu(s) for the stress calculation.

```
Using up to 1 cpu(s) for the symmetric stiffness/mass contributions.

Factoring the system of equations using the unsymmetric spooles solver
Using 1 cpu for spooles.
```

---

<div class="post-metadata">

**Author:** ![irphe](https://avatars.discourse-cdn.com/v4/letter/i/43a26b/32.png) [@irphe](https://calculix.discourse.group/u/irphe)\
**Post date:** [June 28, 2021, 3:26pm UTC](https://calculix.discourse.group/t/running-with-more-cpus/648/2 "2021-06-28T15:26:33Z")

</div>

Hello, if you have compiled Calculix properly, you can use the command **export OMP\_NUM\_THREADS=4** to run it on 4 CPUS

---

<div class="post-metadata">

**Author:** ![imgprojts](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@imgprojts](https://calculix.discourse.group/u/imgprojts)\
**Post date:** [June 29, 2021, 11:37pm UTC](https://calculix.discourse.group/t/running-with-more-cpus/648/3 "2021-06-29T23:37:55Z")

</div>

> [@irphe](#):
>
> llo, if you have compiled Calculix properly, you can use the command **export OMP\_NUM\_THREADS=4** to run it on 4 CPUS

FredXG may also want to take a look at using Prepomax as the pre and post processor. In the tools-\>settings-\>calculix menu you can change the number of processors to use. I have used it with 1, 8, 16 and 64. with 16 CPU’s my home machine seems well balanced (as in, it uses lots of CPU and ram all the time until the problem is completed). On a work machine with 64 cores, the machine seemed to resolve problem sections quickly, but with a lot of idle time in between. As of yet, I have no idea what to change to make the machine keep using processors and be more productive. I recall a paper a few years ago that showed CPU # as a way to accelerate FEA to be a diminishing returns solution after about 8 CPUs. But like I said, 16 cores seems to be just peachy.

---

<div class="post-metadata">

**Author:** ![carlomontec](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@carlomontec](https://calculix.discourse.group/u/carlomontec)\
**Post date:** [June 30, 2021, 10:00am UTC](https://calculix.discourse.group/t/running-with-more-cpus/648/4 "2021-06-30T10:00:06Z")

</div>

Assuming you are in Windows, you can also set the Enviroment variables, so there are set all the time in your computer:

> **[Set Environment Variable in Windows {How-To} | phoenixNAP KB](https://phoenixnap.com/kb/windows-set-environment-variable)**
>
> This tutorial covers different ways to set, view, and unset environment variables in Windows using the GUI, Command Prompt and PowerShell.