Futuremark releases the results of a year's worth of benchmarks to verify the long-running rumour of Apple slowing down older iPhones in order to encourage the upgrade cycle-- something the company does not, in fact, do!
For those not in the know, Futuremark is the developer of popular benchmarking software 3DMark. The benchmark is available for iDevices, and allows reviewers and power users to check the performance of their iPhone before and after the installation of apps and updates. Since 2016 Futuremark has stored over 100000 of such comparisons for 7 iPhone models across 3 different iOS versions, providing "a unique insight into the everyday performance of each iPhone model over time."
The result? Contrary to the conspiracy theory iPhone performance does not degrade over time. 3D Mark aggregates the results for iPhone 5, 6 and 7 using both a CPU and GPU benchmark, and performance remains remarkably consistent-- even in the case of an iPhone 5s upgraded to iOS 9, 10 and 11.