In an effort to provide faster performance during solution, Mechanical APDL supports offloading key solver computations onto graphics cards to accelerate those computations. Only high-end graphics cards, the ones with the most amount of cores and memory, can be used to accelerate the solver computations. For details on which GPU devices are supported and the corresponding driver versions, see the GPU requirements outlined in the Windows Installation Guide and the Linux Installation Guide.

It is important to understand that a GPU does not replace the CPU core(s) on which a simulation typically runs. One or more CPU cores must be used to run the Mechanical APDL program. The GPUs are used in support of the CPU to process certain calculations. The CPU continues to handle most operations and will automatically offload some of the time-intensive parallel operations performed by certain equation solvers. These parallel solver operations can usually be performed much faster on the highly parallel architecture of a GPU, thus accelerating these solvers and reducing the overall time to solution.

GPU acceleration can be used with both shared-memory parallel (SMP) processing and distributed-memory parallel (DMP) processing. In SMP processing, one or multiple GPU accelerator devices can be utilized during solution. In DMP processing, one or multiple GPU accelerator devices per machine or compute node can be utilized during solution.

As an example, when using DMP processing on a cluster involving eight compute nodes with each compute node having two supported GPU accelerator devices, either a single GPU per node (a total of eight GPU cards) or two GPUs per node (a total of sixteen GPU cards) can be used to accelerate the solution. The GPU accelerator device usage must be consistent across all compute nodes. For example, if running a simulation across all compute nodes, it is not possible to use one GPU for some compute nodes and zero or two GPUs for the other compute nodes.

On machines containing multiple GPU accelerator devices, the program automatically selects the GPU accelerator device (or devices) to be used for the simulation. The program cannot detect if a GPU device is currently being used by other software, including another Mechanical APDL simulation. Therefore, in a multiuser environment, users should be careful not to oversubscribe the GPU accelerator devices by simultaneously launching multiple simulations that attempt to use the same GPU (or GPUs) to accelerate the solution. For more information, see Oversubscribing GPU Hardware in the troubleshooting discussion.

The GPU accelerator capability is supported on Windows 64-bit and Linux x64 platforms.

Note, some GPU cards may contain multiple GPUs in them, and a GPU may contain multiple GPU compute engines. HPC licensing for Mechanical APDL is per CPU core and GPU (not per GPU compute engine). You can use up to four GPUs and CPU cores combined without any HPC licensing (for example, one CPU core and three GPUs). To use more than four, you need one or more Ansys HPC licenses or Ansys HPC Pack licenses. For more information see HPC Licensing in the Ansys, Inc. Licensing Guide.