The most commonly used FFT algorithms *by far* are the
power-of-two-length FFT algorithms.
The Prime Factor Algorithm (PFA) and Winograd Fourier Transform Algorithm (WFTA) require somewhat fewer multiplies, but the overall difference
usually isn't sufficient to warrant the extra difficulty.
This is particularly true now that most processors have single-cycle pipelined hardware multipliers,
so the total operation count is more relevant.
As can be seen from the following table, for similar lengths the split-radix algorithm is comparable
in total operations to the Prime Factor Algorithm, and is considerably better than the WFTA, although the
PFA and WTFA require fewer multiplications and more additions.
Many processors now support single cycle multiply-accumulate (MAC) operations; in the power-of-two algorithms all multiplies can be combined with adds in MACs, so the number of additions is the most
relevant indicator of computational cost.

FFT length | Multiplies (real) | Adds(real) | Mults + Adds | |
---|---|---|---|---|

Radix 2 | 1024 | 10248 | 30728 | 40976 |

Split Radix | 1024 | 7172 | 27652 | 34824 |

Prime Factor Alg | 1008 | 5804 | 29100 | 34904 |

Winograd FT Alg | 1008 | 3548 | 34416 | 37964 |

*any*DFT length