According to software company Futuremark, Apple doesn't intentionally slow down older iPhones
when it releases new software updates as a way to encourage its customers to buy new devices. MacRumors reports: Starting in 2016, Futuremark collected over 100,000 benchmark results for seven different iPhone models across three versions of iOS, using that data to create performance comparison charts to determine whether there have been performance drops in iOS 9, iOS 10, and iOS 11. The first device tested was the iPhone 5s, as it's the oldest device capable of running iOS 11. iPhone 5s, released in 2013, was the first iPhone to get a 64-bit A7 chip, and iOS 11 is limited to 64-bit devices. Futuremark used the 3DMark Sling Shot Extreme Graphics test and calculated all benchmark scores from the iPhone 5s across a given month to make its comparison. The higher the bar, the better the performance, and based on the testing, GPU performance on the iPhone 5s has remained constant from iOS 9 to iOS 11 with just minor variations that Futuremark says "fall well within normal levels." iPhone 5s CPU performance over time was measured using the 3DMark Sling Shot Extreme Physics test, and again, results were largely consistent. CPU performance across those three devices has dropped slightly, something Futuremark attributes to "minor iOS updates or other factors."