There is a conspiracy theory going around that claims Apple deliberately throttles older iPhones in order to convince customers to buy the latest model. Geekbench – and some Reddit users – have found a kernel of truth in the ramblings. iOS does throttle performance, but not for the reason people think it does.
A theory about the iOS performance throttling first appeared in the iPhone subreddit, providing evidence of the discovery. User TeckFire noted a performance difference in his iPhone 6S after he replaced the battery. With the benchmarks going from a Geekbench score of 1466 Single and 2512 Multi to a more impressive 2526 Single and 4456 Multi.
This, in turn, led Geekbench developer John Poole to also investigate the matter. Poole discovered that the performance difference begins to appear in iOS 10.2.1; which contained a patch designed to fix a sudden shutdown bug that was appearing on old iPhones.
The prevailing theory now is that iOS 10.2.1 down throttles the processor to keep it from drawing too much power. It kicks in when the battery degrades past a certain level; causing a very notable drop in performance. Although it achieves the goal of preserving battery life and preventing the phone from suddenly turning off.
Not everyone has been able to replicate the results of the test, although the methods currently in use are far from laboratory standards. If anything, it may offer a glimmer of hope for those on older iPhones who want to restore the performance of their devices.