However, a Reddit user has found out the reason for this. While this may not be the only reason but it seems to be a satisfactory one. It might be when the battery in your iPhone wears out, iOS automatically lowers the iPhone CPU speed to give you a day of battery life. Naturally, this directly affects the performance of your iPhone.
Old iPhone batteries causing the slowdown?
According to the screenshots on Reddit, battery replacement helps give a massive speed boost to your old Apple iPhone. It was seen that an iPhone 6s got a GeekBench score of 1466 (Single core) and 2512 (Multi-core) with a worn-out battery. The user himself put the battery to about 20% wear out. However, after replacing the battery, the same iPhone 6s managed to register a clock speed of 2526 (Single core) and 4456 (Multi-core) on the same benchmarking app. The reason for this is also simple – when your battery starts to wear out, iOS tries to optimize the hardware for a full day battery life. In an attempt to preserve battery, iOS lowers your CPU clock speed which directly affects performance. This way, you get a full day of battery but the user experience itself degrades over time. To fix this, you can simply go to your Apple repair shop and get the battery replaced.
Are all iPhones affected?
Fortunately no, not all the iPhone models are prone to this issue. So far, Reddit comments have pointed at the iPhone 6s having the issue. The iPhone 7 and up are free from this problem because they have dedicated low-power cores. Thanks to these new cores, iPhone 7 and up use lesser power and use the more powerful cores when there’s heavy usage.
