Virtualizovaná prostředí mají dost často problém s měřením času, navíc:
Testing JavaScript performance on Windows XP (Update: and Vista) is a crapshoot, at best. With the system times constantly being rounded down to the last queried time (each about 15ms apart) the quality of performance results is seriously compromised. Dramatically improved performance test suites are going to be needed in order to filter out these impurities, going forward.
více viz
http://ejohn.org/blog/accuracy-of-javascript-time/
Názor k článku
Velký test rychlosti JavaScriptu v prohlížečích
