# Very bad GROMACS performance

**URL:** <https://gromacs.bioexcel.eu/t/very-bad-gromacs-performance/6764>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [July 6, 2023, 10:09am UTC](https://gromacs.bioexcel.eu/t/very-bad-gromacs-performance/6764 "2023-07-06T10:09:20Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Matthew1310](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@Matthew1310](https://gromacs.bioexcel.eu/u/Matthew1310)\
**Post date:** [July 6, 2023, 10:09am UTC](https://gromacs.bioexcel.eu/t/very-bad-gromacs-performance/6764/1 "2023-07-06T10:09:20Z")

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GROMACS version: lastest  
GROMACS modification: No  
Hello !  
I have a PC with Risen 5 3600X CPU (6 core/6 threads) and an RTX 4070 as GPU.  
I installed GROMACS on Ubuntu with WSL2.  
I have terrible performance with gpu on MDRUN.  
I suppose there is an error in the compilation of GROMACS because during mdrun I see  
6OpenMP Threads  
but just 1 MPI threads  
I think that the problem may be the only one MPI thread.  
So I should re-install grimaces with these options :  
`DGMX_THREAD_MPI=ON` , -DGMX\_GPU=CUDA  
And launch my simulation with :  
mdrun -ntmpi 6 -nb gpu  
Is it correct ?  
Any other advice to boost performance ?

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**Author:** ![Carsten](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@Carsten](https://gromacs.bioexcel.eu/u/Carsten)\
**Post date:** [July 7, 2023, 9:28am UTC](https://gromacs.bioexcel.eu/t/very-bad-gromacs-performance/6764/2 "2023-07-07T09:28:36Z")

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Hi Matthew,

take a look at

[https://manual.gromacs.org/documentation/current/user-guide/mdrun-performance.html](https://manual.gromacs.org/documentation/current/user-guide/mdrun-performance.html)

This page gives many tips for better simulation performance.

Best,  
Carsten

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<div class="post-metadata">

**Author:** ![Matthew1310](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@Matthew1310](https://gromacs.bioexcel.eu/u/Matthew1310)\
**Post date:** [July 7, 2023, 10:20am UTC](https://gromacs.bioexcel.eu/t/very-bad-gromacs-performance/6764/3 "2023-07-07T10:20:04Z")

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Ok.  
I solved as I said.  
Reinstalling GROMACS in the correct manner now the performance is 10x faster than before.