Run results for: UI Thread vs. Worker

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36 OPR/42.0.2393.517

Browser: Opera 42

Operating system: Linux

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
UI Thread	1843.7 Ops/sec
Worker Thread	72275.5 Ops/sec

Script Preparation code:

window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL || window.oURL;
  
  var code = `function single(iterations) {
    let o; 
  
    for (let i = 1; i < iterations; i += 1) {
      o = { a: Math.random() };
      o.a += Math.random();
    }
  
    return o;
  }
  
  onmessage = function (e) {
    postMessage(single(e.data.iterations));
    close();
  };`;
  
  var bb = new Blob([code], { type: 'text/javascript' });
  var bbURL = URL.createObjectURL(bb);
  var worker = new Worker(bbURL);
  
  function parallel(iterations) {
    worker.onmessage = function (e) {
      URL.revokeObjectURL(bbURL);
      deferred.resolve();
    };
    worker.postMessage({ iterations });
  }
  
  function single(iterations) {
    let o; 
  
    for (let i = 1; i < iterations; i += 1) {
      o = { a: Math.random() };
      o.a += Math.random();
    }
  
    return o;
  }

Tests:

UI Thread
single(1000);
Worker Thread
parallel(1000);

Run results for: UI Thread vs. Worker

UI Thread

Worker Thread