With this year’s iPhone 13 Pro and Pro Max, Apple finally brought its ProMotion display technology from the iPad Pro over to some of its phones. The feature allows the new high-end iPhones to refresh screen content up to 120 times per second, thereby creating a much smoother interface experience. The effect is most noticeable when scrolling, but almost every aspect of a UI can benefit from a higher refresh rate.
Am I correct in seeing that UIView.animateWithDuration APIs aren't clocked at 120Hz on iPhone 13? On UIScrollView, system ones, and Metal by the looks of it, rest is still 60Hz? pic.twitter.com/t3MeM9cj0E— Christian Selig (@ChristianSelig) September 24, 2021
Unfortunately, it looks like the iPhone 13 Pro and Pro Max limit their ProMotion displays in one notable context. According to reports spotted by 9to5Mac, the phones cap some animations in third-party apps to 60Hz. Scrolling and full-screen transitions render as expected but other animations do not. The effect is apparently jarring. What makes it worse is that it’s not something you’ll see when using any software from Apple; the iPhone 13 Pro and Pro Max do not enforce that same limitation on the company’s apps.
What makes the situation particularly confusing is that the iPad Pro does not have a similar limit. It has treated first- and third-party apps equally since it was released in 2017. A source told 9to5Mac the iPhone’s implementation may have something to do with battery life considerations. At the very least, code in iOS 15 suggests the limitation isn’t a bug. Either way, we’ve reached out to Apple for more information, and we’ll update this article when we hear back from the company.
Update 9/25 12:05PM ET: Apple says some apps will need to update to make full use of the iPhone 13 Pro's 120Hz refresh rate. The company will also fix a bug limiting speeds in some apps that use Core Animation.