2 research outputs found
The inherent overlapping in the parallel calculation of the Laplacian
Producción CientíficaA new approach for the parallel computation of the Laplacian in the Fourier domain is presented. This numerical problem inherits the intrinsic sequencing involved in the calculation of any multidimensional Fast Fourier Transform (FFT) where blocking communications assure that its computation is strictly carried out dimension by dimension. Such data dependency vanishes when one considers the Laplacian as the sum of n independent one-dimensional kernels, so that computation and communication can be naturally overlapped with nonblocking communications. Overlapping is demonstrated to be responsible for the speedup figures we obtain when our approach is compared to state-of-the-art parallel multidimensional FFTs.Junta de Castilla León (grant number VA296P18
Overlapping of Communication and Computation in nb3dfft for 3D Fast Fourier Transformations
For efficiency and accuracy of Direct Numerical Simulations(DNS) of turbulent flows pseudo-spectral methods can be employed,where the governing equations are solved partly in Fourier space. Theinhouse-developed 3d-FFT library nb3dfft is optimized to the specialneeds of pseudo-spectral DNS, particularly for the scientific code psOpen,used by the Institute for Combustion Technology at RWTH Aachen Uni-versity. In this paper we discuss the method of overlapping communica-tion and computation of multiple FFTs at the same time