Run results for: DataView vs Uint32Array debunking myth

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/135.2 Mobile/15E148 Safari/605.1.15

Browser: Mobile Safari 18

Operating system: iOS 18.3.1

Device Platform: Mobile

Date tested: one year ago

Uint32

686.7M/s

DataView

15K/s

View exact numbers

Test name	Executions per second
✓ Uint32	686,710,272 Ops/sec
DataView	15,090 Ops/sec

Script Preparation code:

var size = 4 * 4096;
var buf = new ArrayBuffer(size);
var view = new DataView(buf);
var byte = new Uint32Array(buf);

var data = [];

for (let i = 0; i < size; i++) {
	data[i] = 100*Math.random();
}

Tests:

DataView
for (let i = 0; i < size / 4; ++i) { view.setUint32(i, data[i]); }
Uint32
for (let i; i < size / 4; ++i) { byte[i] = data[i]; }