  A comparison of PGI OpenACC, FORTRAN CUDA, and Nvidia CUDA pseudospectral
methods on a single GPU and GCC FORTRAN on single and multiple CPU cores is
reported. The GPU implementations use CuFFT and the CPU implementations use
FFTW. Porting pre-existing FORTRAN codes to utilize a GPUs is efficient and
easy to implement with OpenACC and CUDA FORTRAN. Example programs are provided.
