# Using tune\_pme

**URL:** https://gromacs.bioexcel.eu/t/using-tune-pme/538
**Category:** User discussions
**Created:** [July 20, 2020, 8:35am UTC](https://gromacs.bioexcel.eu/t/using-tune-pme/538 "2020-07-20T08:35:06Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![jpw](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jpw](https://gromacs.bioexcel.eu/u/jpw)
#### Post date: [July 20, 2020, 8:35am UTC](https://gromacs.bioexcel.eu/t/using-tune-pme/538/1 "2020-07-20T08:35:07Z")

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GROMACS version: 2020.1  
GROMACS modification: Yes

Hi,

I’ve been trying to use tune\_pme (mostly out of curiosity), but have not gotten it to work.

The system I’d like to use tune\_pme for is run with `gmx_mpi mdrun -deffnm production -cpi production.cpt` and everything works fine.

The same .tpr is used for attempting to run tune\_pme like this:

`export MPIRUN="/apps/GROMACS/2020.1-CrayGNU-19.10/bin/gmx_mpi"`  
(location of binary given by `which gmx_mpi`)  
`gmx_mpi tune_pme -s production.tpr -mdrun "gmx_mpi mdrun" -np 36`

Unfortunately, it always complains that -np is an “unknown command line option” in benchtest.log, even when I don’t specify it and leave it to default. It is trying to execute the command “gmx\_mpi -np 36 gmx\_mpi mdrun -version -maxh 0.001”.

In the standard error, it gives “Fatal error: Need an MPI-enabled version of mdrun. This one (gmx\_mpi mdrun) seems to have been compiled without MPI support”.

I’ve tried quite a few modifications of the command, including the suggestion from [https://www.mail-archive.com/gromacs.org\_gmx-users@maillist.sys.kth.se/msg39637.html](https://www.mail-archive.com/gromacs.org_gmx-users@maillist.sys.kth.se/msg39637.html), so I would be grateful for any pointers what to try.

Best,  
Julian