Run results for: One big array or one per object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:94.0) Gecko/20100101 Firefox/94.0

Browser: Firefox 94

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Big array read in chunks	24230.9 Ops/sec
Small array read	25507.4 Ops/sec
Big array read simple	27921.6 Ops/sec
non-typed big array read in chunks	24704.5 Ops/sec
non-typed big array read simple	28916.4 Ops/sec
Big array read realistic	37430.9 Ops/sec
small array read realistic	39975.7 Ops/sec

Script Preparation code:

var count = 100;
var bigArr = new Float32Array(16 * count);
var bigArr2 = Array(16 * count);
var arrs = new Array(count);
for (let i = 0; i < count; i++) {
  var a = arrs[i] = new Float32Array(16);
  for (let x = 0; x < 16; x++) {
    var v = Math.random();
    a[x] = v;
    bigArr[i * 16 + x] = v;
    bigArr2[i * 16 + x] = v;
  }
}

var t;

Tests:

Big array read in chunks
t = 0; let c = 16 * count; for (let i = 0; i < c; i += 16) { for (let x = 0; x < 16; x++) { t += bigArr[i + x]; } }
Small array read
t = 0; for (const a of arrs) { for (let x = 0; x < 16; x++) { t += a[x]; } }
Big array read simple
t = 0; let c = 16 * count; for (let i = 0; i < c; i++) { t += bigArr[i]; }
non-typed big array read in chunks
t = 0; let c = 16 * count; for (let i = 0; i < c; i += 16) { for (let x = 0; x < 16; x++) { t += bigArr2[i + x]; } }
non-typed big array read simple
t = 0; let c = 16 * count; for (let i = 0; i < c; i++) { t += bigArr2[i]; }
Big array read realistic
t = 0; let c = 16 * count; for (let i = 0; i < c; i += 16) { t += bigArr[i + 0]; t += bigArr[i + 1]; t += bigArr[i + 2]; t += bigArr[i + 3]; t += bigArr[i + 4]; t += bigArr[i + 5]; t += bigArr[i + 6]; t += bigArr[i + 7]; t += bigArr[i + 8]; t += bigArr[i + 9]; t += bigArr[i + 10]; t += bigArr[i + 11]; t += bigArr[i + 12]; t += bigArr[i + 13]; t += bigArr[i + 14]; t += bigArr[i + 15]; }
small array read realistic
t = 0; for (const a of arrs) { t += a[0]; t += a[1]; t += a[2]; t += a[3]; t += a[4]; t += a[5]; t += a[6]; t += a[7]; t += a[8]; t += a[9]; t += a[10]; t += a[11]; t += a[12]; t += a[13]; t += a[14]; t += a[15]; }

Run results for: One big array or one per object

Big array read in chunks

Small array read

Big array read simple

non-typed big array read in chunks

non-typed big array read simple

Big array read realistic

small array read realistic