Many Apple users may feel that if their models are older, they will become much more stuttered after upgrading the system version. Take the iPadmini used by Xiaobian a few years ago as an example, the factory preset IOS7 is very smooth, in order to upgrade the third-party input method to IOS8, it will produce a little sense of caton, and even run a QQ after the last upgrade to IOS9 can be stuck into PPT. In most people's cognition, mobile phone updates are an optimization of the mobile phone system, and from the experience point of view, Apple has made the optimization of the mobile phone a negative optimization.
However, there has been no conclusive evidence for Apple to negatively optimize the old iPhone by updating it, and it seems that this rumor has been officially acquiesced after Apple recently agreed to settle a class action lawsuit that lasted six years.
The content of the class action lawsuit said that Apple deliberately slowed down the speed of iPhone 4S devices after the 2015 iOS 9 update, and consumers also said that the reason for updating the download was because Apple made false publicity about the new operating system. They argue that Apple misstates that iOS 9 is compatible with the iPhone 4S and will improve or "enhance" the performance of customers who download the software update. Instead, the plaintiffs argue that iOS 9 significantly degraded the performance of their iPhone 4S devices.
The class action lawsuit resulted in Apple awarding $20 million to compensate iPhone 4S owners in New York and New Jersey, though customers who believe they are entitled to $15 must submit a statement of affected process describing a significant performance drop after downloading iOS 9 or any version of it to their iPhone 4S.