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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36 Edg/125.0.0.0

Browser: Chrome 125

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

DataView

23.5M/s

Uint8Array by byte

23.4M/s

Uint8Array with set

1.1M/s

with Float64Array

901K/s

View exact numbers

Test name	Executions per second
✓ DataView	23,506,538 Ops/sec
Uint8Array by byte	23,443,086 Ops/sec
Uint8Array with set	1,138,772 Ops/sec
with Float64Array	901,478 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();
}

Tests:

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