# How Is the MATLAB filter() Function So Fast?

How is the filter() implemented in MATLAB? How is it so fast?
What's the fastest implementation of a FIR filter?

• You may look on the code of Octave and Scipy. – Mark Feb 23 at 5:35

Actually it seems MATLAB implementation of the filter() function is pretty straight forward and not fast.

For a fast implementation, have a look at FilterM by Jan Simon.

## Update

In the latest releases of MATLAB (From R2016b and above) the performance of the filter() function has improved.
The metdhos to accelerate those operations are usually based on:

1. Utilizing SIMD Operations (SSE / AVX in x86).