Peter Wapperom, Antony N. Beris, and Mark A. Straka
A new transpose split method for three-dimensional FFTs:
performance on an Origin2000 and Alphaserver cluster
Parallel Computing 32 (2006) 1-13
We discuss a new transpose split method for parallel computations
of three-dimensional Fourier transforms. By splitting the data along
two dimensions over the processors it allows for a higher degree of
parallelization than the original transpose split method.
The traditional transpose split method involves one alltoall
communication. The new method involves two
communication steps in which each processor performs
an "alltoall" communication in groups.
The performance of the new method has been evaluated
using MPI on an Origin2000 and an Alphaserver cluster and
compared with the traditional transpose split method.
We found that the extra communication step introduced in
the new method only slightly increases
communication time. However, an efficient parallelization
depends critically on how fast the
communications can be performed.
Parallel 3D Fourier/Chebyshev transform; Fast Fourier transform;
direct numerical simulation; transpose split method