# Simulation time drastically slows down midway through **URL:** \ **Category:** User discussions\ **Tags:** mdrun, gpu\ **Created:** [March 27, 2024, 4:13am UTC](https://gromacs.bioexcel.eu/t/simulation-time-drastically-slows-down-midway-through/8707 "2024-03-27T04:13:16Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![evanc](https://avatars.discourse-cdn.com/v4/letter/e/13edae/32.png) [@evanc](https://gromacs.bioexcel.eu/u/evanc)\ **Post date:** [March 31, 2024, 5:37pm UTC](https://gromacs.bioexcel.eu/t/simulation-time-drastically-slows-down-midway-through/8707/4 "2024-03-31T17:37:12Z")
I resolved this issue. Here’s the solution: I edited my `mdrun` command to include `-update gpu`. Thus, the full command is as follows: `gmx mdrun -s test.tpr -v -x test.xtc -c test.gro -nb gpu -bonded gpu -pme gpu -nstlist 400` This aligns with the suggestions from this [NVIDIA blog](https://developer.nvidia.com/blog/creating-faster-molecular-dynamics-simulations-with-gromacs-2020/). I initially did not include the `-update gpu` argument because I was using the Nose-Hoover themostat, which for whatever reason does not work with the `-update` argument. Because I was not committed to Nose-Hoover for any particular reason besides aligning with prior studies, I have opted to use the `v-rescale` thermostat in my .mdp file (as suggested [here](https://gromacs.bioexcel.eu/t/reducing-wait-gpu-state-copy-for-single-gpu-runs/3555/3)). `v-rescale` works with the `-update gpu` argument in `mdrun`. The simulation now runs in the expected time, i.e., ~30 hours. So matter resolved. ![temp_v2](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/2/2eba5ce43584e556fa311390bdd29220e65041a9.png) ![power_v2](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/f/f11f5847e601d03aa80c39bcc1ae1608b8e9c08f.png) --- _[View the full topic](https://gromacs.bioexcel.eu/t/simulation-time-drastically-slows-down-midway-through/8707)._