"plumed not supported" with "-update gpu" on gmx2023.2-plumed2.10.0

[joan.c...@gmail.com]

Dear all,

Following on my gmx-plumed google colab adventures, I have encountered the following (see mdrun output below). Basically, if I add the -update gpu option to mdrun, gromacs complains that plumed isn't supported. The calculation runs fine with update on the cpu, but obviously it's slower. Is that a plumed problem or a gromacs problem?

Thanks!

'''

:-) GROMACS - gmx mdrun, 2023.2-plumed_2.10.0_dev (-: Executable: /usr/local/gromacs/bin/gmx Data prefix: /usr/local/gromacs Working dir: /content/MD Command line: gmx mdrun -update gpu -v -deffnm prod -nsteps 25000000 -plumed plumed.dat Compiled SIMD is AVX2_256, but CPU also supports AVX_512 (see log). Reading file prod.tpr, VERSION 2023.2-plumed_2.10.0_dev (single precision) Overriding nsteps with value passed on the command line: 25000000 steps, 5e+04 ps Changing nstlist from 10 to 100, rlist from 1 to 1.154 Update groups can not be used for this system because atoms that are (in)directly constrained together are interdispersed with other atoms ------------------------------------------------------- Program: gmx mdrun, version 2023.2-plumed_2.10.0_dev Source file: src/gromacs/taskassignment/decidegpuusage.cpp (line 792) Function: bool gmx::decideWhetherToUseGpuForUpdate(bool, bool, PmeRunMode, bool, bool, gmx::TaskTarget, bool, const t_inputrec&, const gmx_mtop_t&, bool, bool, bool, bool, bool, bool, const gmx::MDLogger&) Inconsistency in user input: Update task on the GPU was required, but the following condition(s) were not satisfied: PLUMED is not supported. For more information and tips for troubleshooting, please check the GROMACS website at http://www.gromacs.org/Documentation/Errors -------------------------------------------------------

'''

[Giovanni Bussi]

Hi,

this is expected unfortunately. PLUMED needs coordinates on the CPU to work.

Giovanni

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[joan.c...@gmail.com]

Hi Giovanni,

Thanks for confirming that. 

I guess they have changed the way coordinates are dealt with within Gromacs so I probably there is no easy workaround, however I just wanted to say that in gmx2021.4-plumed-2.9.0-dev it used to work, in case it's useful for anybody else.

Cheers

[Pratibha M bt21d130]

Hi,

   I am running replica exchange simulations. Since its taking a lot of time when i use only CPU, I tried to enable GPU, but I am getting this error.

The command I used is: mpirun -np 4 gmx_mpi mdrun -v -deffnm reht -plumed plu.dat -multidir 0 1 2 3  -replex 500001 -hrex -gpu_id 0 -nb gpu

Program:     gmx mdrun, version 2021.7-plumed-2.8.3

Source file: src/gromacs/taskassignment/decidegpuusage.cpp (line 302)
Function:    bool gmx::decideWhetherToUseGpusForNonbonded(gmx::TaskTarget, const std::vector<int>&, gmx::EmulateGpuNonbonded, bool, bool, bool)
MPI rank:    1 (out of 4)

Inconsistency in user input:
Nonbonded interactions on the GPU were required, but not supported for these
simulation settings. Change your settings, or do not require using GPUs.

For more information and tips for troubleshooting, please check the GROMACS
website at http://www.gromacs.org/Documentation/Errors
-------------------------------------------------------