Apple is one of several large tech firms accused of using “planned obsolescence” as a way of encouraging consumers to upgrade to the latest device. Last week, a Reddit user whose iPhone 6s had been slowing down found it received a massive performance boost when they replaced the battery, leading to an extensive thread on the subject. Today, Geekbench founder, John Poole, published an article that backed up these findings and looked deeper into the issue.

Poole plotted the kernel density of Geekbench 4 single-core scores for the iPhone 6s and iPhone 7 running different versions of iOS. “The difference between iOS 10.2 and 10.2.1 is too abrupt to be just a function of battery condition. I believe […] that Apple introduced a change to limit performance when battery condition decreases past a certain point,” he explained.

Poole is referring to the update Apple rolled out in iOS version 10.2 designed to address an iPhone 6s battery issue that was causing the handsets to shut down for no apparent reason. It’s thought that problem was a result of degraded batteries being unable to handle the iPhone’s clock speeds. Apple’s “fix” apparently involved limiting performance on older phones to prevent the shutdowns. Poole says performance issues would only get worse over time, something he blames on battery age and changes to iOS.

[...] it appears the problem is widespread, and will only get worse as phones (and their batteries) continue to age. See, for example, the difference between the distribution of iPhone 6s scores between 10.2.1 and 11.2.0.

While Apple’s solution is far from ideal, it’s better than the alternative, adds Poole. “Because degraded batteries last much less and end up with a lower voltage Apple’s solution was to scale down CPU performance, it doesn’t solve anything and is a bad experience […] but it’s better than having your device shutdown at 40% when you need it the most.”

So, it seems Apple really has been throttling performance in older iPhones, but only as a way to decrease power draw and prevent them from draining their batteries too quickly. Poole adds that Apple appears to have added a similar fix to iOS 11.2.0 for the iPhone 7.

This fix will also cause users to think, “my phone is slow so I should replace it” not, “my phone is slow so I should replace its battery.” This will likely feed into the “planned obsolescence” narrative.

Apple has not commented on the latest Geekbench findings.