Is Apple doing something to slow down old iPhones?

Geekbench developer Primate Labs' Poole found that performance of iPhones running on older batteries slows down by observing the devices' performance readings.

He discovered that changing the battery on an iPhone 6S almost doubled its performance; the devices started behaving like a new one.

He swapped the battery suspecting there was something wrong with the iOS as it only showed lower charge levels.

Poole carried out more tests using iPhone 6S and iPhone 7 by running different iOS versions.

He observed not only batteries but a "code" present on iOS 10.2.0 and above slowed down the devices.

On iOS 10.2.1, iPhone 6S's performance struggled; with the latest iOS 11.2, the performance worsened.

With iOS 10.2.1, iPhone 7 didn't show much difference, but iOS 11.2 affected the performance.

Later, iOS developer Guilherme Rambo followed up John Poole's research and discovered that a secret power mode, which Poole had theorized, is present inside Apple's iOS code. This mode was responsible for the iPhones' performance slowdown.

On Twitter, he revealed that the power mode named "Powerd" is responsible for controlling the CPU/GPU speed and power usage based on iPhone battery health."

Powerd (power daemon) mode limits the maximum clock speed of the device's CPU and GPU when the battery is low. It has a failsafe to ensure that iPhones don't heat up during usage or burst into flames.

However, it also slows down the device as its battery gets old to avoid heating up issues. It is different from the iPhone's Low Power Mode.

Many say the problem is not the presence of Powerd in the iOS but the fact that iPhone/iPad users are not being informed that their device performance is slowing down because of Powerd.

Apple has so far not responded on the matter to give an explanation regarding the same.

Poole said until Apple responds, "This will likely feed into the 'planned obsolescence' narrative."