Hi Everyone, I have compiled QE 5.0.2 on a computer with AMD interlagos processors, using the acml, compiling with openmp enabled, and submitting jobs with PBS. I've had a speed up using 2 openmp threads per mpi process.
I've been trying to do the same on another computer, that has MOAB as the scheduler, E5 series xeon processors (E5-2660) and uses the Intel MKL (E5-2660). I'm pretty sure hyperthreading has been turned off, as each node has two sockets and 16 cores in total. I've seen a slow down in performance using OpenMP and MPI, but have read that this might be the case in the documentation. I'm waiting in the computer's queue to run the following: #!/bin/bash #MOAB -l "nodes=2:ppn=16" #MOAB -l "walltime=0:01:00" #MOAB -j oe #MOAB -N pwscf_calc #MOAB -A readmsd02 #MOAB -q bbtest cd "$PBS_O_WORKDIR" module load apps/openmpi/v1.6.3/intel-tm-ib/v2013.0.079 export PATH=$HOME/bin:$PATH export OMP_NUM_THREADS=2 mpiexec -np 16 -x OMP_NUM_THREADS=2 -npernode 8 -bind-to-socket -display-map -report-bindings pw_openmp_5.0.2.x -in benchmark2.in > benchmark2c.out I just wondered if anyone had any tips on the settings or flags for hybrid MPI/OpenMP with the E5 Xeon processors? All the best, Ben Palmer Student @ University of Birmingham, UK
