VASP: Difference between revisions

Vasp-GPU executable files run on both GPU and CPU of a node. Basically calculation on GPU of a node is much more expensive than CPU, therefore we highly recommend to perform a benchmark using one or 2 GPU to make sure they are using maximum GPU utilization. Fig.1 show a benchmark of Si crystal contains 256 Si-atoms in the unit-cell. Blue, black and red lines show performance as a function of Number of CPU=0, 1, and 2 respectively. It shows the performance for GPU=1, CPU=2 and  CPU=1 is more than 5 times better than GPU=0 and CPU=1 which clearly shows that using GPU is beneficial. However, a comparison between calculation with GPU=1 and GPU=2 indicates that there no much performance gain from GPU=1 and GPU=2. In fact GPU utilization for GPU=2 is around 50%. Therefore we recommend users to perform a benchmark like this for their own system to make sure they are wasting any computer resources.