How to use VASP 6.2.0 on swing.

We have built the open_acc version of VASP.6.2 for swing. You will generatlly find your calculations will run several times faster on GPUs than on a broadwell node. The speedup you get will depend on the size of your model and the values of KPAR and NSIM in your INCAR file. See https://www.vasp.at/wiki/index.php/OpenACC_GPU_port_of_VASP for details. We have used the silicaIFPEN benchmark to get typical speedups. The silicaIFPEN benchmark uses the PBE functional for a supercell model of a defect in cristobalite containing 240 atoms. A single GPU was 2.94 times faster than a broadwell node, two gpus are 60% faster than one GPU, and four gpus are 60% faster than two GPUs. Eight GPUs are 10% faster than four GPUS. We have not seen good scaling for more than four GPUs for this benchmark.

Not all of VASP has been ported to GPUS. Semi-Local and hybrid functionals has been ported. The hybrid funtionals should be very fast on the GPUs. RPA is still a work in progress and it does not run significantlly faster on the GPUs than on the broadwells.

An example script can be found in /soft/vasp/6.2.0/swing/fast.sh