2, a sense of fluency
When iPhone7 is in iOS 13.4, the sliding frame sometimes falls off. Opening the APP is slow, and the slider drop in some apps becomes lower. When upgrading to iOS 15.7, the frequency of sliding frame drop becomes lower, the opening speed of app is obviously improved, and sliding in some apps is smoother.
Step 3 feel feverish
IPhone7 does not play games in daily light use of iOS 13.4, and its fever is obvious. Although the temperature is gradually decreasing at present, the heat seems to have not dropped much. After upgrading to iOS 15.7, the heat is obviously reduced. Even playing a big game like the glory of the king, the fever temperature is lower than before, and the number of game frames is always stable.
4. Signal perception
For example, when iOS 13.4 enters the elevator, the signal will drop directly to 1, and the signal will not recover immediately after exiting the elevator. Sometimes it is necessary to manually turn on the flight mode and turn it off to get the signal. After upgrading to iOS 15.7, you can also get 2 frames of signals after entering the elevator, and return to normal signals 5 seconds after exiting the elevator.
IPhone7 has been upgraded from iOS 13.4 to iOS 15.7, which has indeed improved in all aspects. I have to say that Apple has broken its heart for iOS 15.7, deeply polished the system and brought positive optimization. If the old model wants to provide for the aged, it can be upgraded to iOS 15.7.