# Performance of SMD simulation

**URL:** <https://gromacs.bioexcel.eu/t/performance-of-smd-simulation/12748>\
**Category:** User discussions\
**Tags:** mdp-parameters, mdrun-performance, simulation-setup\
**Created:** [October 9, 2025, 9:05pm UTC](https://gromacs.bioexcel.eu/t/performance-of-smd-simulation/12748 "2025-10-09T21:05:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mpedraza](https://avatars.discourse-cdn.com/v4/letter/m/df788c/32.png) [@mpedraza](https://gromacs.bioexcel.eu/u/mpedraza)\
**Post date:** [October 9, 2025, 9:05pm UTC](https://gromacs.bioexcel.eu/t/performance-of-smd-simulation/12748/1 "2025-10-09T21:05:05Z")

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GROMACS version: 2024.3-plumed\_2.9.3  
GROMACS modification: Yes/No

I want to know if there is a way to find out the performance (ns/day) I am getting for my system by the end of an SMD when it fails due to box size constraints. In theory it should be in the log file, but since it fails it is never printed. I know this is a very simple question but I can’t find a good workaround.

Thanks in advance

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**Author:** ![obZehn](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/obzehn/32/2629_2.png) [@obZehn](https://gromacs.bioexcel.eu/u/obZehn)\
**Post date:** [October 10, 2025, 8:51am UTC](https://gromacs.bioexcel.eu/t/performance-of-smd-simulation/12748/2 "2025-10-10T08:51:40Z")

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The simplest way in my opinion would be to

i) rerun the simulations by setting `-nsteps` to a number that doesn’t lead to crashes, so the simulation can properly close and write all statistics or  
ii) open the `.log` file of the simulation you have, check for a line starting with `Started mdrun` that reports the exact time the simulation started, and from the last number of steps reported in the log file compute the performance (you can get the time of the end of the simulation by looking at the last time the log file was written).