Use OpenCL for GPU support in Stan via the brms interface. Only some Stan functions can be run on a GPU at this point and so a lot of brms models won't benefit from OpenCL for now.
opencl(ids = NULL)A brmsopencl object which can be passed to the
opencl argument of brm and related functions.
For more details on OpenCL in Stan, check out https://mc-stan.org/docs/2_26/cmdstan-guide/parallelization.html#opencl as well as https://mc-stan.org/docs/2_26/stan-users-guide/opencl.html.