One of the improvements in iOS 9 concerns battery life, as Apple plans to further increase it with help of a Low Power mode that can be enabled at any time by the user when their remaining charge gets too low. However, don’t be surprised if your iPhone 6 or any iOS 9-ready device takes a pretty big performance hit once Low Power mode is enaled.
Now that Geekbench 3 supports iOS 9, MacRumors compared the performance of the iPhone 6 running in regular and Low Power modes.
Unsurprisingly, iOS 9 will significantly reduce processor performance in order to increase battery life — Apple actually tells you that Low Power will not only reduce performance, but it’ll also disable mail fetching, background app refresh, motion effects and animated wallpapers.
In regular mode, the iPhone 6 scored 1606/2891 for single-core/multi-core performance. Once Low Power mode is activated, Geekbench will register a much lower performance scores: 1019/1751.
The same goes for the iPhone 5s, which registered 1386/2511 in regular mode and 816/1405 in Low Power mode.
A yellow battery icon indicates that Low Power mode is active on a phone in iOS 9. To activate it at any time, simply go to Settings, then Battery, and you’ll see a toggle for Low Power mode at the top. Additionally, a Low Power prompt will hit your screen every time the iPhone has just 10% or 20% charge left, offering you the option to activate it.