3D FFTs on HPCx (IBM vs FFTW)
Adrian Jackson, Gavin J. Pringle · 2003
Fast Fourier Transforms (FFTs) are an essential part of many scientific codes: from Molecular Dynamics to Climate Modelling. It is, therefore, evident that HPCx requires efficient methods for performing FFTs and related calculations. This study compares the performance of the two main FFT libraries on HPCx: IBM’s ESSL/PESSL and FFTW. Both serial and parallel (distributedmemory only) 3D complex-to-complex FFT routines are investigated, and the performance of the two different libraries is discussed. In general, the ESSL and FFTW serial 3D FFT routines are comparable. For parallel FFTs, the PESSL library is, in general, slightly faster, however, FFTW has better parallel efficiency. Some further comments are made about the overall performance of HPCx, and its impact of the use of FFT library routines. 1