Hi all,
I’m using lammps20201029 on a platform with 2x EPYC 7702 CPUs (64 cores each), and 4x Nvidia RTX 6000 GPUs; OpenMPI 4.0.5; and testing with the LJ melt input script.
If I don’t use the GPU package, the script runs fine. If I use the GPU package with 63 or fewer cores, it runs fine.
However, if I use the GPU package with 64 or more cores, I get the first two lines of output:
LAMMPS (29 Oct 2020)
using 1 OpenMP thread(s) per MPI task
And then nothing. The job doesn’t end, and the CPU cores are fully loaded according to top. Looking at nvidia-smi, I see the memory for the processes are loaded onto the GPUs, but they have no utilization.
Do you have any ideas?
Michael Jacobs
Dobrynin Group
Department of Chemistry
UNC Chapel Hill