Accelerating a Climate Physics Model with OpenCL

Open Computing Language (OpenCL) is fast becoming the standard for heterogeneous parallel computing. It is designed to run on CPUs, GPUs, and other accelerator architectures. By implementing a real world application, a solar radiation model component widely used in climate and weather models, we show that OpenCL multi-threaded programming and execution model can dramatically increase performance even on CPU architectures. Our preliminary investigation indicates that low-level vector instructions and code representations in OpenCL contribute to dramatic performance improvement over the serial version when compared with the execution of the serial code compiled across various compilers on multiple platforms with auto vectorization flags. However, the portability of OpenCL implementations needs to improve, even for CPU architectures.