Development and application of a hybrid programming environment on an ARM/DSP system for high performance computing

The nCore Brown-Dwarf system has a unique architecture where each node is comprised of two different low-power System-on-Chip (LPSoC) processors from Texas Instruments; the ARM/DSP Keystone II SoC and the DSP based Keystone I SoC. These LPSoC processors have, through use of the C66x multi-core DSP, been shown to be capable of running floating-point intensive HPC application codes. However, it is non-Trivial to run such codes across all processing elements of a node simultaneously. This paper demonstrates a hybrid programming environment that combines OpenMP, OpenCL and MPI to enable application execution across multiple Brown-Dwarf nodes. This environment is evaluated using two diverse application codes. The first is Level-3 BLAS matrix multiplication (GEMM), which is a standard HPC floating-point intensive benchmark. The second is a unique real-world scientific code for biostructure based drug design developed by the Southwest Research Institute called Rhodium. Performance and energy-efficiency of Rhodium is presented alongside comparisons with conventional x86 based HPC systems with attached accelerators. Results indicate that the Brown-Dwarf system remains competitive with contemporary systems for memory-bound computations.