array vs typed array vs object for points

arr.js

'use strict';

var v8 = require('v8');

var N = 1000000;

var values = [];
for (var i = 0; i < 2 * N; i++) values.push(Math.random());

var memStart = v8.getHeapStatistics().used_heap_size;

console.time('create');
var points = [];
for (i = 0; i < N; i++) {
    var p = [
        values[i * 2],
        values[i * 2 + 1]
    ];
    points.push(p);
}
console.timeEnd('create');

console.log('memory used: ' + (v8.getHeapStatistics().used_heap_size - memStart));

console.time('pow');
for (i = 0; i < N; i++) {
    p = points[i];
    p[0] = p[0] * p[0];
    p[1] = p[1] * p[1];
}
console.timeEnd('pow');

obj.js

'use strict';

var v8 = require('v8');

var N = 1000000;

var values = [];
for (var i = 0; i < 2 * N; i++) values.push(Math.random());

var memStart = v8.getHeapStatistics().used_heap_size;

console.time('create');
var points = [];
for (i = 0; i < N; i++) {
    var p = {
        x: values[i * 2],
        y: values[i * 2 + 1]
    };
    points.push(p);
}
console.timeEnd('create');

console.log('memory used: ' + (v8.getHeapStatistics().used_heap_size - memStart));

console.time('pow');
for (i = 0; i < N; i++) {
    p = points[i];
    p.x = p.x * p.x;
    p.y = p.y * p.y;
}
console.timeEnd('pow');

result.txt

~/projects/point-test → node -v
v7.2.1

~/projects/point-test → node typed.js 
create: 1647.736ms
memory used: 154543544
pow: 19.621ms

~/projects/point-test → node arr.js 
create: 133.100ms
memory used: 68876040
pow: 43.794ms

~/projects/point-test → node obj.js 
create: 156.931ms
memory used: 44730944
pow: 8.678ms

typed.js

'use strict';

var v8 = require('v8');

var N = 1000000;

var values = [];
for (var i = 0; i < 2 * N; i++) values.push(Math.random());

var memStart = v8.getHeapStatistics().used_heap_size;

console.time('create');
var points = [];
for (i = 0; i < N; i++) {
    var p = new Float64Array(2);
    p[0] = values[i * 2];
    p[1] = values[i * 2 + 1];

    points.push(p);
}
console.timeEnd('create');

console.log('memory used: ' + (v8.getHeapStatistics().used_heap_size - memStart));

console.time('pow');
for (i = 0; i < N; i++) {
    p = points[i];
    p[0] = p[0] * p[0];
    p[1] = p[1] * p[1];
}
console.timeEnd('pow');