This paper introduces open-source computational fluid dynamics software named open computational fluid dynamic code for scientific computation with graphics processing unit (GPU) system (OpenCFD-SCU), developed by the authors for direct numerical simulation of compressible wall-bounded turbulence. This software is based on the finite difference method and is accelerated by the use of a GPU, which provides an acceleration by a factor of more than 200 compared with central processing unit (CPU) software based on the same algorithm and a number of Message Passing Interface processes, and the running speed of OpenCFD-SCU with just 512 GPUs exceeds that of CPU software with 130 000 CPUs. GPU-Stream technology is used to implement overlap of comp...