GROMACS version: 2024.4
GROMACS modification: Yes
What I can’t use my GPU?
During the MD simulation, CPU usage reaches 100%, while GPU utilization increases to only 7%. Running the command gmx mdrun -deffnm md_0_1 -v -nb gpu or gmx mdrun -deffnm md_0_1 -v results in the same performance.
Hi!
“Utilization” of CPU or GPU is a rather meaningless metric and should be interpreted carefully. For starters, 100% CPU usage (as reported by, e.g., top) means a full utilization of one core, while a 100% GPU usage would mean full utilization of the entire GPU. Also, I only see Xwayland (graphics server) among the list of GPU processes; it does not look like GROMACS was running on the GPU when you took that screenshot.
Even with these caveats, it is not necessary that best performance equals highest utilization.
If you want some suggestions on improving performance, take a look at our tuning guide and check the performance counters reported at the end of the md_0_1.log file.
Running the command
gmx mdrun -deffnm md_0_1 -v -nb gpuorgmx mdrun -deffnm md_0_1 -vresults in the same performance.
This is expected, since -nb gpu is the default when a GPU is detected.