One of the more interesting features in iOS 9 is the new Low Power mode that throttles your devices power in the name of saving power. With the iPhone’s notoriously small batteries, this feature could prove to be exceptionally useful, but how much power are you sacrificing? Well, if a benchmark test that MacRumors performed on an iPhone 6 Plus is anything to go by, the Low Power mode could reduce your iPhone’s power by as much as 40%.