index.html

<script src="typed.js"></script> 

typed.js

const count = 10;
const arraySize = count * 6;
const runs = 1e4;

// set up typed array test

let a = new Float32Array(arraySize).map(Math.random);
let b = new Float32Array(arraySize).map(Math.random);
let c = new Float32Array(arraySize).map(Math.random);

function typedPerf() {
    for(var i = 0; i < arraySize; ++i) {
        b[i] = a[i];
        c[i] = a[i];
    }
}

// set up push/shift array test

let d = new Array(arraySize).fill(1).map(Math.random);
let e = new Array(arraySize).fill(1).map(Math.random);
let f = new Array(arraySize).fill(1).map(Math.random);

function pushPerf() {
    for(var i = 0; i < 12; ++i) {
        e.shift();
    }
    for(var i = 0; i < 12; ++i) {
        e.push(d[i]);
    }
    for(var i = 0; i < 12; ++i) {
        f.pop();
    }
    for(var i = 0; i < 12; ++i) {
        f.unshift(d[i]);
    }
}

function perf(fn, name) {
    let avg = 0;
    for(var i = 0; i < runs; ++i) {
        a = new Float32Array(arraySize).map(Math.random);
        b = new Float32Array(arraySize).map(Math.random);
        c = new Float32Array(arraySize).map(Math.random);
        d = new Array(arraySize).fill(1).map(Math.random);
        e = new Array(arraySize).fill(1).map(Math.random);
        f = new Array(arraySize).fill(1).map(Math.random);
        let start = performance.now();
        fn();
        let end = performance.now();
        let time = end - start;
        avg += time;
    }
    avg /= runs;
    console.log(`${name}: ${avg} ms`);
}


perf(typedPerf, 'typed array copy');
perf(pushPerf, 'array push/shift');