Charmm36-jul2021 is much slower comparative to charmm36-mar2019

User discussions
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1

GROMACS version:2022.2
GROMACS modification: No

@jalemkul
problem:

Previously I happen to use charmm36-mar2019 but due to few updates in CGenFF server (https://cgenff.umaryland.edu/), I have to switch to new CHARMM ff.

With charmm36-jul2021, my simulation takes twice as much time as charmm36-mar2019.
provided: All other parameters are same as before. I use gmx mdrun -deffnm md_0_10 -v -ntmpi 32 command to run the simulation.

Question:
Is there any evidence that newer version of CHARMM FF are much slower comparative to charmm36-mar2019 or I am doing something wrong with the gmx mdrun command or mdp files?

Thanks

2

There is nothing about the force field that can make the simulation slower. All my tests run at identical speeds. If you’re using the same .mdp files, you should get the same performance. If not, something is going on with your hardware (e.g. too many jobs running at the same time and fighting each other, etc.)