is your requestAnimationFrame dated? http://paulirish.com/2011/requestanimationframe-for-smart-animating/http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating (this link doesn't work properly) When reviewinghttp://updates.html5rocks.com/2012/05/requestAnimationFrame-API-now-with-sub-millisecond-precision which references High Resolution Timehttp://dvcs.w3.org/hg/webperf/raw-file/tip/specs/HighResolutionTime/Overview.html#sec-extenstions-performance-interface The paul irish blog seems to have posted some revisions.. removing the o and ms vendor tags.. but it isn't reflected in his git distribution.. and some of the year old comments make reference to the performance.now() (High Resolution Time) methodology.. and discuss mozilla date.now() issues.. 16.7 ms seems to be the ideal timing.. which I suspect is only possible with the HDT precision.