Solving Poisson's equation using FFT in a GPU cluster

Poisson's equation is present in many scientific computations and its efficient solution is achieved by means of several methods. One of the most efficient methods is the Fast Fourier Transform (FFT), which is very widely used in lots of computational problems. In this work we implement a Poisson solver that uses FFT as base method and runs in a cluster of Graphics Processing Units (GPU). We analyze the execution of our implementation to find the main bottlenecks and we compare the results to a CPU based solver. The results show a good scalability up to 16 GPUs, the number of GPUs we have available. Moreover, although the main time consuming part of the process is the network communication, the GPU implementation is about 2.5 times faster than the CPU implementation.