Executing JavaScript code will definitely involve the processor cache and a high-resolution timer is accessible via browser performance API.

Chrome will soon throttle JavaScript timers in the background, so the browser uses significantly less power. Written by Liam Tung, Contributing Writer July 6, 2020 at 4:08 a.m. PT ...

The search giant has announced that starting with Chrome 86, it will ship a new feature that limits JavaScript timer wake ups in background web pages.

The change in Javascript timer wake-ups should apply to all the major versions of Chrome including Chrome for Windows, Mac, Linux, Chrome OS, and Android.