I went across change logs of MobileSafari in iOS 6 where it states:
WebKit no longer always creates hardware-accelerated layers for elements with the -webkit-transform: preserve-3d option. Authors should stop using this option as a way to get hardware acceleration
Does there exist any list of hardware accelerated CSS properties ?
These aspects of your document can be accelerated by the GPU:
More on this here http://www.html5rocks.com/en/tutorials/speed/html5/
Maybe this article will help toohttp://indiegamr.com/ios6-html-hardware-acceleration-changes-and-how-to-fix-them/
And this one http://mobile.smashingmagazine.com/2012/06/21/play-with-hardware-accelerated-css/