Many believe that Apple is pushing CSS annimations and transforms as a possible alternative to Flash. Indeed, months before that functionality was avalable in mainstream Safari, it was available on the iPhone and iPod touch. But Flash isn’t on the iPhone and one of the reasons usually given is that it kills the CPU and by extension the battery.
Well, we took a look at the CPU usage of the simple falling leaves example on Webkit.org. Surprisingly, it used anywhere from 70-90% of a CPU core on a 2.0 GHz Unibody MacBook…
Obviously this is a beta browser using new technology and some optimizations will undoubtedly be done. However, it is a bad sign for those who believe CSS animations will be able to take the place of Flash without costing similar CPU and battery penalties.
Just as a comparison, watching a hi-def flash movie in Vimeo eats about the same CPU juice.