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Typed Array performance in JavaScript

I was looking at a few JavaScript implementations of Conway’s Game of Life and I was a little underwhelmed by their performance, so I started wondering how much was related to Array performance in JavaScript.

There’s a better option for arrays of ints: Typed Arrays, the smallest object they can store is an 8 bit byte (I only need a boolean), but that’s still a lot less complicated than a full JS object.

I tested on Firefox and Chrome on a modern MacBook Pro and an old Windows 7 machine. In every case, typed arrays were faster than plain arrays.

Interestingly, Chrome was slightly faster operating on 32 bit words

On Chrome the typed arrays were ~3x faster, on Firefox they were 25% faster. Somehow Firefox managed to take over 12x as long on my old windows box.

Browser (Machine) Int8Array Int32Array Array
Chrome (MacBook Pro) 216.541ms 198.340ms 723.414ms
Firefox (MacBook Pro) 199.7ms 198.96ms 252.67ms
Chrome (Old Win7) 668.000ms 564.000ms 1878.000ms
Firefox (Old Win7) 7355.06ms 7163.35ms 9494.34ms

To test yourself, you can use this code (output goes to the browser console).

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