JSFiddle - React, Tailwind, and code Playground

JavaScript

var limit        = 1000000000;
var intervals    = 0;
var totalTime    = new Date();
var startTime    = new Date();

var uid = setInterval(
    function () {
        // final lap?
        if (intervals == 9) clearInterval(uid);
        
        for (i = 0; i < limit; i += 1) {
            // just working the CPU
        }
        // reduce the iterations
        limit = limit / 10;   
        intervals += 1;        
        
        console.log('Interval ' + intervals +' Time elapsed : ' + (new Date() - startTime));
        // reset the time
        startTime    = new Date();
    }, 250, 9);