June 23, 2022
Title: FFTU: the fastest Fourier transform in Utrecht (applied MI-talk, also at 4pm)
Speaker: Rob Bisseling
he multidimensional Fast Fourier Transform (FFT) is at the heart of many grid-based scientific computations, including weather and climate prediction, and (quantum) molecular dynamics.
In this talk, we present a parallel algorithm for the FFT in higher dimensions. This algorithm generalizes the cyclic-to-cyclic 1D parallel algorithm to a cyclic-to-cyclic multidimensional parallel algorithm, with only a single all-to-all communication step in most practical cases.
We present our multidimensional implementation FFTU which utilizes the sequential FFTW program (the "fastest Fourier transform in the West") for its local FFTs. Our experimental results for 2D, 3D, and 5D on up to 4096 cores of the new Dutch national supercomputer Snellius show that FFTU is competitive with the state-of-the-art and that for 3D it may be the fastest, not in only in Utrecht, but also beyond.