README.md

FFT benchmarks for NumPy* and SciPy*

This FFF benchmarking framework is useful to measure FFT performance of different NumPy and SciPy versions and vendors. In addition to Python implementation we also able to benchmark native code (MKL DFTI) implementations of these benchmarks with similar command-line interfaces.

Python benchmarks

The following example create benchmarking environment for NumPy and SciPy FFT available from intel channel in conda:

conda create -n intel_env -c intel numpy scipy
conda activate intel_env

To run the FFT benchmark framework in Python, type:

python fft_bench.py [-h] [args] size

The framework perform initial warmup call to respective FFT API, and then performs 24 (default) timings for 16 (default) repetitions of FFT computations in the loop. These 24 measurements are aggregated to report minimum, median and maximum timings, which are printed to STDOUT.

Other printed lines which start with 'TAG: ' are printed for information purposes.

Examples

Benchmark a 2D out-of-place FFT of a complex128 array of size (10000, 10000):

python fft_bench.py 10000x10000

Benchmark a 1D in-place FFT of a float32 array of size 100000000, print only 5 measurements, only compute the first half of the conjugate-even DFT coefficients, and allow the FFT backend to only use one thread:

python fft_bench.py -P -r -t 1 -d float32 -o 5 100000000

Benchmark a 3D in-place FFT of a complex64 array of size 1001x203x3005, printing only 5 measurements, each of which average over 24 inner loop computations:

python fft_bench.py -P -d complex64 -o 5 -i 24 1001x203x3005

Native benchmarks

Compiling on Linux

• To compile, source compiler and run make.
• Run with ./fft_bench.

Compiling on Windows

• Source compiler and MKL, then run win_compile_all.bat.

  > "C:\Program Files (x86)\IntelSWTools\compilers_and_libraries\windows\bin\compilervars.bat intel64"
  > "C:\Program Files (x86)\IntelSWTools\compilers_and_libraries\windows\mkl\bin\mklvars.bat intel64"
  > win_compile_all.bat
  

• To run, run fft_bench.exe. Note that long options are not supported on Windows. Use short options instead.

Examples

Benchmark a 2D out-of-place FFT of a complex128 array of size (10000, 10000):

./fft_bench 10000x10000

Benchmark a 1D in-place FFT of a float32 array of size 100000000, print only 5 measurements, only compute the first half of the conjugate-even DFT coefficients, allow the FFT backend to only use one thread, and cache the DFTI descriptor between inner loop runs (similar behavior to mkl_fft for single dimensional FFTs).

./fft_bench -P -c -r -t 1 -d float32 -o 5 100000000

Benchmark a 3D in-place FFT of a complex64 array of size 1001x203x3005, printing only 5 measurements, each of which average over 24 inner loop computations:

./fft_bench -P -d complex64 -o 5 -i 24 1001x203x3005

Usage

usage: ./fft_bench [args] size
Benchmark FFT using Intel(R) MKL DFTI.

FFT problem arguments:
  -t, --threads=THREADS    use THREADS threads for FFT execution
                           (default: use MKL's default)
  -d, --dtype=DTYPE        use DTYPE as the FFT domain. For a list of
                           understood dtypes, use '-d help'.
                           (default: complex128)
  -r, --rfft               do not copy superfluous harmonics when FFT
                           output is even-conjugate, i.e. for real inputs
  -P, --in-place           allow overwriting the input buffer with the
                           FFT outputs
  -c, --cached             use the same DFTI descriptor for the same
                           outer loop, i.e. "cache" the descriptor

Timing arguments:
  -i, --inner-loops=IL     time the benchmark IL times for each printed
                           measurement. Copies are not included in the
                           measurements. (default: 16)
  -o, --outer-loops=OL     print OL measurements. (default: 5)

Output arguments:
  -p, --prefix=PREFIX      output PREFIX as the first value in outputs
                           (default: 'Native-C')
  -H, --no-header          do not output CSV header. This can be useful
                           if running multiple benchmarks back-to-back.
  -h, --help               print this message and exit

The size argument specifies the input matrix size as a tuple of positive
decimal integers, delimited by any non-digit. For example, both
(101, 203, 305) and 101x203x305 denote the same 3D FFT.

See also

"Accelerating Scientific Python with Intel Optimizations" by Oleksandr Pavlyk, Denis Nagorny, Andres Guzman-Ballen, Anton Malakhov, Hai Liu, Ehsan Totoni, Todd A. Anderson, Sergey Maidanov. Proceedings of the 16th Python in Science Conference (SciPy 2017), July 10 - July 16, Austin, Texas