Battery saving feature (Low Power Mode) on iOS 9 can give an iPhone up to 3 hours more of battery life. This mode is automatically turned on when the battery capacity of the device is only about 10% or 20%. However, when this feature works, your iPhone will have to exchange many things including performance.
Recently, Mac Rumors tested battery saving function (Low Power Mode) on iOS 9. And the result is not positive because performance of the machine can be significantly reduced. This parameter is measured by Geekbench 3 benchmark test, the score recorded is 1019. For the multi-core test, it scored 1751. That’s at least 1100 less than the normal mode score.
This means that iPhone 6 will operate slower than 40%. In fact, the power of the iPhone 6 in low power mode will be equivalent to the iPhone 5s.
In this mode, your iPhone will automatically disable the background task, reduce application processing speed, brightness, disable mail notification system.
Low power mode is not stranger to the majority of users now. Because Google has applied this feature on Android 5.0 Lollipop. Even some other manufacturers such as Samsung, HTC used it on Android devices from 2 ~ 3 years ago.