# Regression tests fail on multiple cores, pass on one core

**URL:** <https://gromacs.bioexcel.eu/t/regression-tests-fail-on-multiple-cores-pass-on-one-core/626>\
**Category:** User discussions\
**Created:** [August 5, 2020, 8:55pm UTC](https://gromacs.bioexcel.eu/t/regression-tests-fail-on-multiple-cores-pass-on-one-core/626 "2020-08-05T20:55:07Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![novalex](https://avatars.discourse-cdn.com/v4/letter/n/6f9a4e/32.png) [@novalex](https://gromacs.bioexcel.eu/u/novalex)\
**Post date:** [August 5, 2020, 8:55pm UTC](https://gromacs.bioexcel.eu/t/regression-tests-fail-on-multiple-cores-pass-on-one-core/626/1 "2020-08-05T20:55:07Z")

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GROMACS version: 2016.5  
GROMACS modification: No

I am trying to run GROMACS 2016.5 with mdrun built with MPI enabled. After I build, I download the regression tests and run them. On one node, everything works, but when I try the regression tests on two nodes I get the following test failures: 1 Complex Test fails (Orientation Restraints) and 5 Essential Dynamics tests fail.

 ![FailedTestsCombinedImage](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/1X/ce5d3354336fadf23936763fae199af2442204d5.png)

I’ve combined both sets of failed tests into one image because new users are only allowed one image per post.

I looked into downloading a new version but the shared supercomputer I’m running this on only has cmake version 2.8.12.2. Newer versions require later versions of cmake to compile, with the exception of GROMACS 2016.6. I checked GROMACS 2016.6’s changelog but none of the changes in it look like they relate to mpi, so I don’t think that would help.

Does anyone know why I’m getting these test failures and if there’s anything I can do about it? Any help is greatly appreciated.

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<div class="post-metadata">

**Author:** ![novalex](https://avatars.discourse-cdn.com/v4/letter/n/6f9a4e/32.png) [@novalex](https://gromacs.bioexcel.eu/u/novalex)\
**Post date:** [August 7, 2020, 5:49am UTC](https://gromacs.bioexcel.eu/t/regression-tests-fail-on-multiple-cores-pass-on-one-core/626/2 "2020-08-07T05:49:58Z")

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I was able to upgrade GROMACS after all. Sadly it didn’t make my problems go away. Here’s my new error, but this particular error is resolved [Gmx\_mpi doesn't run](https://gromacs.bioexcel.eu/t/gmx-mpi-doesnt-run/633)