How does Flickr's parallax scrolling work?

Question

Flickr's new design makes use of parallax scrolling on its section backgrounds. Parallax scrolling on retina displays is generally choppy (eg: http://inoviacapital.com/), but it is very smooth on Flickr.

How does Flickr accomplish smooth parallax scrolling on retina displays? I went through their source and found several parallax-related functions, but can't figure out exactly how they do it.

Answer 1

Looks like they are using transforms instead of background-position as in your example.

Check out: http://www.css3maker.com/css3-transform.html;