[saagarjha]

There's a screenshot in the blog post that shows "0%" CPU usage. I doubt that Cal wanted to make it seem like animations were "free" but I do want to caution people that just because the GPU is now handling drawing doesn't mean the usual concerns with animations with regards to performance don't apply (I am not going to wade into the UI aspects of when to use animations). Animations are best used in moderation, for short interactions rather than running continuously all the time, even when drawn with graphics hardware. It's nice to push 60 (or 120) fps every once in a while but your app should really not be drawing at all most of the time. That's fewer frames to display in software, and on newer iPhones with ProMotion that's also going to mean fewer display refreshes. Your users, and their batteries, will thank you.

(But really, moving all these things to CoreAnimation is really nice, kudos to all involved!)