BurstFFT

BurstFFT is an FFT (Fast Fourier Transform) implementation in
high-performance C# with Unity’s Burst compiler.

This repository contains the following three variants of Fourier transform
implementation.

• NaiveDFT: Unoptimized naive C# implementation of DFT
• BurstDFT: Vectorized/parallelized DFT implementation, optimized with Burst
• BurstFFT: Vectorized Cooley-Tukey FFT implementation, optimized with Burst

You can also enable parallelization on BurstFFT by disabling the SINGLE_THREAD
symbol in BurstFft.cs.

Results

Windows Desktop (Ryzen 7 3700X, 3.6GHz, 8 cores)

MacBook Pro 15 Late 2013 (Core i7, 2.3GHz, 4 cores)

Thoughts and Findings

• It’s quite easy to parallelize DFT with Unity’s C# Job System. The more cores
  it has, the faster it runs.
• Although the parallelized DFT runs quite fast compared to the unoptimized one,
  it never beat the single-threaded FFT.
• The traditional Cooley-Tukey FFT is hard to parallelize in a performant way.
  The results above show that the 8-core BurstFFT runs slower than the 4-core
  one.