FDPS: a novel framework for developing high-performance particle simulation codes for distributed-memory systems

We have developed FDPS (Framework for Developing Particle Simulator), which enables researchers and programmers to develop high-performance particle simulation codes easily. The basic idea of FDPS is to separate the program code for complex parallelization including domain decomposition, redistribution of particles, and exchange of particle information for interaction calculation between nodes, from actual interaction calculation and orbital integration. FDPS provides the former part and the users write the latter. Thus, a user can implement, for example, a high-performance N- body code, only in 120 lines. In this paper, we present the structure and implementation of FDPS, and describe its performance on two sample applications: gravitational N-body simulation and Smoothed Particle Hydrodynamics simulation. Both codes show very good parallel efficiency and scalability on the K computer. FDPS lets the researchers concentrate on the implementation of physics and mathematical schemes, without wasting their time on the development and performance tuning of their codes.