Run results for: copy ArrayBuffer: DataView vs Uint8Array.set vs Float64Array.set vs by bytes v2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser: Chrome 138

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Uint8Array by byte

14.0M/s

DataView

13.7M/s

Uint8Array with set

722K/s

with Float64Array

701K/s

View exact numbers

Test name	Executions per second
✓ Uint8Array by byte	13,996,286 Ops/sec
DataView	13,717,086 Ops/sec
Uint8Array with set	721,786 Ops/sec
with Float64Array	700,629 Ops/sec

Script Preparation code:

var size = 0xFFFF;
var buf = new ArrayBuffer(size);
var view = new DataView(buf);
var byte = new Uint8Array(buf);

var data = new Uint8Array(size);

for (let i = 0; i < size; i++) {
	data[i] = 100*Math.random();
}

window._data = data;
window._buf = buf;

Tests:

DataView
data[Date.now()%data.length] = 43; for (let i; i < size; i++) { view.setUint8(i, data[i]); }
Uint8Array by byte
data[Date.now()%data.length] = 43; for (let i; i < size; i++) { byte[i] = data[i]; }
Uint8Array with set
data[Date.now()%data.length] = 43; byte.set(data);
with Float64Array
data[Date.now()%data.length] = 43; (new Float64Array(buf, 0, size/8)) .set(new Float64Array(data.buffer, 0, size/8));