# GPU Inconsistency User Input/Feature Not Implemented

**URL:** <https://gromacs.bioexcel.eu/t/gpu-inconsistency-user-input-feature-not-implemented/228>\
**Category:** User discussions\
**Created:** [June 1, 2020, 9:39pm UTC](https://gromacs.bioexcel.eu/t/gpu-inconsistency-user-input-feature-not-implemented/228 "2020-06-01T21:39:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rgumpper](https://avatars.discourse-cdn.com/v4/letter/r/47e85d/32.png) [@rgumpper](https://gromacs.bioexcel.eu/u/rgumpper)\
**Post date:** [June 1, 2020, 9:39pm UTC](https://gromacs.bioexcel.eu/t/gpu-inconsistency-user-input-feature-not-implemented/228/1 "2020-06-01T21:39:15Z")

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GROMACS version: 2020.2  
GROMACS modification: No

I’ve been trying to run the output from Charmm-gui’s membrane builder using 2 GPUs.

My problem is arising during the minimization step thus far:

Input:  
gmx\_gpu mdrun -v -ntmpi 1 -nb gpu -bonded gpu -pme -gpu -npme 1 -deffnm step6.0\_minimization

Error:  
Feature not implemented:  
Cannot compute PME interactions on a GPU, because PME GPU does not support not  
a dynamical integrator.

Input removing PME calculation:  
gmx\_gpu mdrun -v -ntmpi 1 -nb gpu -bonded gpu -deffnm step6.0\_minimization

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

Here is my mdp input:  
define = -DPOSRES -DPOSRES\_FC\_BB=4000.0 -DPOSRES\_FC\_SC=2000.0 -DPOSRES\_FC\_LIPID=1000.0 -DDIHRES -DDIHRES\_FC=1000.0  
integrator = steep  
emtol = 1000.0  
nsteps = 5000  
nstlist = 10  
cutoff-scheme = Verlet  
rlist = 1.2  
vdwtype = Cut-off  
vdw-modifier = Force-switch  
rvdw\_switch = 1.0  
rvdw = 1.2  
coulombtype = pme  
rcoulomb = 1.2  
;  
constraints = h-bonds  
constraint\_algorithm = LINCS

Any feed back or help would be appreciated to at least point me in the right direction. As I havent been able to pinpoint it through googling.

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**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\
**Post date:** [June 1, 2020, 10:11pm UTC](https://gromacs.bioexcel.eu/t/gpu-inconsistency-user-input-feature-not-implemented/228/2 "2020-06-01T22:11:11Z")

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> [@rgumpper](#):
>
> Error:  
> Feature not implemented:  
> Cannot compute PME interactions on a GPU, because PME GPU does not support not  
> a dynamical integrator.

This means you can only run the actual MD simulations using the GPU. Run energy minimization using CPU.

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<div class="post-metadata">

**Author:** ![rgumpper](https://avatars.discourse-cdn.com/v4/letter/r/47e85d/32.png) [@rgumpper](https://gromacs.bioexcel.eu/u/rgumpper)\
**Post date:** [June 1, 2020, 10:13pm UTC](https://gromacs.bioexcel.eu/t/gpu-inconsistency-user-input-feature-not-implemented/228/3 "2020-06-01T22:13:00Z")

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Ahhh thank you very much! That’s good to know!