[gmx-users] The problem of utilizing multiple GPU

[sunyeping]

Dear everyone,

I am trying to do simulation with a workstation with 72 core and 8 geforce 1080 GPUs.
When I do not assign a certain GPU with the command:
      gmx mdrun -v -deffnm md
all GPUs are used and but the utilization of each GPU is extremely low (only 1-2 %), and the simulation will be finished after several months.  
In contrast, when I assign the simulation task to only one GPU:
gmx mdrun -v -gpu_id 0 -deffnm md
the GPU utilization can reach 60-70%, and the simulation can be finished within a week. Even when I use only two GPU:
 gmx mdrun -v -gpu_id 0,2 -deffnm md

the GPU utilizations are very low and the simulation is very slow.

I think I may missuse the GPU for gromacs simulation. Could you tell me what is the correct way to use multiple GPUs?

Best regards