Performance Improvements 

Mathematica 10 introduces further performance improvements in Fourier computation.

Timings for computing discrete Fourier transform in Mathematica 10 and Mathematica 9 as the function of length. The experiment was performed on a 64-bit Windows 7 system equipped with 2 x Intel Xeon E5620 @ 2.40 GHz CPU. The number at the bottom shows how much faster Mathematica 10 is than Mathematica 9.

Timings for padding 2D arrays in Mathematica 10 and Mathematica 9 as the function of side length. The experiment was performed on a 64-bit Windows 7 system equipped with 2 x Intel Xeon E5620 @ 2.40 GHz CPU. The number at the bottom shows how much faster Mathematica 10 is than Mathematica 9.