Run results for: Multiplying lists of vectors - SoA vs AoS vs interlaced array

What's the fastest way to process a list of vectors? Do you go the OO route, with an array of Vector() objects? Do you create a new data structure, using Float32Arrays for x, y, and z? Do you create a single Float32Array and interlace values for x, y, and z within it? Let's find out!

Go to the benchmark

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0

Browser: Firefox 49

Operating system: Windows 7

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
AoS	97.3 Ops/sec
SoA - one loop	32.3 Ops/sec
SoA - one component per loop	53.0 Ops/sec
Interlaced Array - no loop unrolling	52.5 Ops/sec
Interlaced Array - with loop unrolling	53.8 Ops/sec
AoS (bracket notation)	94.1 Ops/sec

Script Preparation code:

var N = 1000000

var x = new Float32Array(N);
var y = new Float32Array(N);
var z = new Float32Array(N);

var interlaced = new Float32Array(3*N);

var vectors = [];

for (var i = 0, li=x.length; i < li; ++i) {
	x[i] = Math.random();
	y[i] = Math.random();
	z[i] = Math.random();
	vectors.push( {x:Math.random(), y:Math.random(), z:Math.random()} );
}

for (var i = 0, li=interlaced.length; i < li; ++i) {
	interlaced[i] = Math.random();
}

Tests:

AoS
var vector; for (var i = 0, li=vectors.length; i < li; ++i) { vector = vectors[i]; vector.x = 2 * vector.x; vector.y = 2 * vector.y; vector.z = 2 * vector.z; }
SoA - one loop
for (var i = 0, li=x.length; i < li; ++i) { x[i] = 2 * x[i]; y[i] = 2 * y[i]; z[i] = 2 * z[i]; }
SoA - one component per loop
for (var i = 0, li=x.length; i < li; ++i) { x[i] = 2 * x[i]; } for (var i = 0, li=y.length; i < li; ++i) { y[i] = 2 * y[i]; } for (var i = 0, li=z.length; i < li; ++i) { z[i] = 2 * z[i]; }
Interlaced Array - no loop unrolling
for (var i = 0, li=interlaced.length; i < li; ++i) { interlaced[i] = 2*interlaced[i]; }
Interlaced Array - with loop unrolling
for (var i = 0, li=interlaced.length; i < li; i+=3) { interlaced[i] = 2*interlaced[i]; interlaced[i+1] = 2*interlaced[i+1]; interlaced[i+2] = 2*interlaced[i+2]; }
AoS (bracket notation)
var vector; for (var i = 0, li=vectors.length; i < li; ++i) { vector = vectors[i]; vector['x'] = 2 * vector['x']; vector['y'] = 2 * vector['y']; vector['z'] = 2 * vector['z']; }

Run results for: Multiplying lists of vectors - SoA vs AoS vs interlaced array

What's the fastest way to process a list of vectors? Do you go the OO route, with an array of Vector() objects? Do you create a new data structure, using Float32Arrays for x, y, and z? Do you create a single Float32Array and interlace values for x, y, and z within it? Let's find out!

AoS

SoA - one loop

SoA - one component per loop

Interlaced Array - no loop unrolling

Interlaced Array - with loop unrolling

AoS (bracket notation)