# PLUMED compatibility with GPU resident mode

**URL:** <https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149>\
**Category:** Developers discussions\
**Created:** [November 1, 2022, 3:46pm UTC](https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149 "2022-11-01T15:46:11Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![pszilard](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/pszilard/32/21_2.png) [@pszilard](https://gromacs.bioexcel.eu/u/pszilard)\
**Post date:** [November 1, 2022, 3:46pm UTC](https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149/1 "2022-11-01T15:46:11Z")

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Hi,

Does anybody know whether PLUMED is compatible with the GROMACS GPU-resident mode?

A user just asked about GROMACS GPU-resident mode with PLUMED and showed some data which may suggest that there may be an incompatibility:

> [@Is using GPU for mdrun \`update\` generally incompatible with PLUMED plugin?](https://gromacs.bioexcel.eu/t/is-using-gpu-for-mdrun-update-generally-incompatible-with-plumed-plugin/5147):
>
> GROMACS version: 2022.3-plumed\_2.8.1 GROMACS modification: Yes, with plumed I am testing an implementation of steered MD with GROMACS and PLUMED. I used alanine dipeptide for the test and tried to add time-dependent harmonic restraints to the Phi and Psi dihedral simultaneously, to induce a conformation change from (-1.5, 1.3) to (1.4, -1.0) in 100ps. I used two ways to add such harmonic restraints, namely, GROMACS pull code and PLUMED MOVINGRESTRAINT, and plotted the CVs evolution along the…

If this is true, users may run into serious silent issues if e.g. the frequency of PLUMED sometimes overlaps with a GROMACS-native operation that downloads/re-uploads GPU state (like COMM removal), but sometimes it does not.

Cheers,  
Szilárd

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<div class="post-metadata">

**Author:** ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)\
**Post date:** [November 1, 2022, 6:50pm UTC](https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149/2 "2022-11-01T18:50:52Z")

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I think it’s highly unlikely that PLUMED is compatible with GPU-resident mode. A modification in GROMACS is needed to tell that the coordinates are always required on the CPU.

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<div class="post-metadata">

**Author:** ![pszilard](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/pszilard/32/21_2.png) [@pszilard](https://gromacs.bioexcel.eu/u/pszilard)\
**Post date:** [November 3, 2022, 12:43pm UTC](https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149/3 "2022-11-03T12:43:34Z")

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That sounds very problematic. If that is verified, I suggest warning users on the forum or even in the release notes of an upcoming release.

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**Author:** ![al42and](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/al42and/32/1393_2.png) [@al42and](https://gromacs.bioexcel.eu/u/al42and)\
**Post date:** [February 1, 2023, 1:15pm UTC](https://gromacs.bioexcel.eu/t/plumed-compatibility-with-gpu-resident-mode/5149/4 "2023-02-01T13:15:36Z")

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PLUMED added a warning: [gromacs 2022.4 patch updated · plumed/plumed2@20f8be2 · GitHub](https://github.com/plumed/plumed2/commit/20f8be272efa268a31af65c56c3c71af8c13402c#diff-f21f46830c34c99766c30157316251b8354efbf1f6359f18b961c7339af97a77R2144)