# Install on cray with mpi

**URL:** <https://gromacs.bioexcel.eu/t/install-on-cray-with-mpi/6581>\
**Category:** User discussions\
**Tags:** installation-error\
**Created:** [June 8, 2023, 7:55pm UTC](https://gromacs.bioexcel.eu/t/install-on-cray-with-mpi/6581 "2023-06-08T19:55:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![biohegedus](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/biohegedus/32/1893_2.png) [@biohegedus](https://gromacs.bioexcel.eu/u/biohegedus)\
**Post date:** [June 8, 2023, 7:55pm UTC](https://gromacs.bioexcel.eu/t/install-on-cray-with-mpi/6581/1 "2023-06-08T19:55:25Z")

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GROMACS version: 2022.5  
GROMACS modification: No

Hi,

I would like to install gmx **mpi for multidir** simulations within **a single node**. Although it is not comparable, but it seems OK on my local box, but I fail to have a good build on our **Cray**. I use gnu prg env, gcc, cuda, the same modules as for building the threaded version. Plus openmpi.  
With the system’s openmpi (5) the gmx\_mpi crashes right after start.  
With my compiled openmpi it runs, but 5-6 times slower than the threaded version (I tested different cmdline arguments to increase performance). This is not a big surprise for me, since I do not think that my openmpi is cuda-aware.

If I want to tune and force to have a better openmpi build, I always fail - it always fails: sometimes with missing libraries during compile time, sometimes with missing libraries at run time. I have tried mpich, too.

Do you have experiences on Cray? Which modules should I use to have a smooth build with high performance?

Sorry, I do not know what specific info to provide to help answering.  
Thanks, Tamas