<html>
<html>
<body>
<p id="p1"></p>
<p id="p2"></p>
<p id="p3"></p>
<script type="text/javascript">
var select = document.createElement("select");
select.classList.add("a-b-c");
select.id = "s";
select.dataset.info = ["a", "b", "c"];
select.info = ["a", "b", "c"];
document.body.appendChild(select);
var el = document.getElementById('s');
var p2 = performance.now();
for (var i = 0; i < 100000; i++) el.dataset.info;
s2 = performance.now() - p2;
var p1 = performance.now();
for (var i = 0; i < 100000; i++) el.className.split("-");
s1 = performance.now() - p1;
var p3 = performance.now();
for (var i = 0; i < 100000; i++) el.info;
s3 = performance.now() - p3;
document.getElementById('p2').innerHTML="dataset time = "+s2;
document.getElementById('p1').innerHTML="name time = "+s1;
document.getElementById('p3').innerHTML="info = "+s3;
</script>
</body>
</html>
//========================
хром
name time = 20.700000000942964
dataset time = 10.800000003655441
info = 1.5999999959603883
//========================
FF
name time = 4.284999999999997
dataset time = 12.164999999999992
info = 1.2399999999999807