Take iPhone 5 S and iPad 3 as an example. Let's take a look at several performance data items before and after iOS 7.1.2 and iOS 8.0. Note that the first two are the shorter the time, the better, the higher the score, the better.
As the main model of the previous generation, the iPhone 5S naturally benefited the most, and the Web performance was improved by 3-12%. What cannot be reflected in the data is the continuous improvement of iOS 8 animation effects, the iPhone 5S is as smooth as ever, and even feels smoother than before.
The third-generation iPad in early 2012 is another situation. After upgrading it with high resolution for the first time, there was a worry: SunSpider slowed down by more than 15%, while Google Octane increased slightly.
In the actual experience, the UI smoothness indeed regresses significantly. What's more, when you use the four-finger gesture to close the application and switch the application list page, the application icons are not rendered, as if the software is not finished yet.
