The aim of this work is to quantitatively evaluate the impact of computation on the energy consumption on ARM MPSoC platforms, exploiting CPUs, embedded GPUs and FPGAs. One of them possibly represents the future of High Performance Computing systems: a prototype of an Exascale supercomputer. Performance and energy measurements are made using a state-of-the-art direct N-body code from the astrophysical domain. We provide a comparison of the time-to-solution and energy delay product metrics, for different software configurations.We have shown that FPGA technologies can be used for application kernel acceleration and are emerging as a promising alternative to “traditional” technologies for HPC, which purely focus on peak-performance than on power-efficiency.