# Run FreeFEM with single precision

**URL:** <https://community.freefem.org/t/run-freefem-with-single-precision/1269>\
**Category:** General Discussion\
**Created:** [October 21, 2021, 7:39am UTC](https://community.freefem.org/t/run-freefem-with-single-precision/1269 "2021-10-21T07:39:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![BeniaminBogosel](https://avatars.discourse-cdn.com/v4/letter/b/3ec8ea/32.png) [@BeniaminBogosel](https://community.freefem.org/u/BeniaminBogosel)\
**Post date:** [October 21, 2021, 7:39am UTC](https://community.freefem.org/t/run-freefem-with-single-precision/1269/1 "2021-10-21T07:39:58Z")

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Hello,  
In the changelog of version 4.6 it is written that FreeFem can solve problems with single precision or 64 bit integers. How can a FreeFem script be run with single precision?

I would like to use this feature to observe the influence of roundoff errors, without the need of using too fine meshes.

Thank you,  
Beniamin

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**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\
**Post date:** [October 21, 2021, 7:43am UTC](https://community.freefem.org/t/run-freefem-with-single-precision/1269/2 "2021-10-21T07:43:25Z")

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This only works with PETSc/SLEPc. You need to have an installation of PETSc/SLEPc with the additional configuration parameter `--with-precision=single`. Let me know if you need assistance with that.

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<div class="post-metadata">

**Author:** ![BeniaminBogosel](https://avatars.discourse-cdn.com/v4/letter/b/3ec8ea/32.png) [@BeniaminBogosel](https://community.freefem.org/u/BeniaminBogosel)\
**Post date:** [October 21, 2021, 8:05am UTC](https://community.freefem.org/t/run-freefem-with-single-precision/1269/3 "2021-10-21T08:05:26Z")

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Thanks for the quick reply. I will think about having a separate installation with single precision.