Over the past few days, there's been a furor regarding the performance of some aging iPhones on the popular Geekbench benchmark under iOS 10.2.1 and newer. Testing by a number of users on Reddit and by Geekbench maker Primate Labs itself revealed that some iPhones were putting up lower single-core Geekbench scores than others with the newer software, leading to outraged iPhone owners and a wide range of inflammatory headlines.
Apple responded to the controversy by acknowledging that recent versions of iOS "smooth out" peak power demands to prevent the annoying sudden shutdowns that have plagued some iPhone owners, but that explanation alone apparently didn't cut it. The company published a letter to customers today that addresses the controversy and outlines some of the reasons for the lowered performance.
As the original post on Reddit suggested, Apple says the performance drop is related to the chemical aging of lithium-ion batteries over their lifetimes. On top of the reasonably common knowledge that older batteries don't run devices for as long as their newer counteparts, Apple adds that aged batteries also don't provide as much peak power to devices, especially in low states of charge. When the SoC inside demands lots of juice (as it might in a peaky load like Geekbench), a compromised battery might not be able to supply enough power, leading to a sudden shutdown.
To avoid these sudden blackouts, Apple changed the way iOS power management works in version 10.2.1 in a way that "dynamically manages the maximum performance of some system components when needed to avoid a shutdown." In short, the device slows down during high transient loads. The company concedes that these power-management provisions can lead to slower app launches and other reductions in performance, though it notes that customers were happy with the reduction in unexpected shutdowns that the new iOS version offered.
Although Apple notes that "of course" a battery replacement would return older iPhones to peak performance, that knowledge was apparently not nearly as obvious to the general public as it was to company insiders. Many users could justifiably have upgraded their slowing iPhones in a begrudging effort to remedy what they may have seen as inexplicable performance losses with age when a simple battery replacement (for $79 from Apple) would have extended the useful life of their devices.
Apple is taking several steps to respond to the controversy these revelations have created. For one, it'll cut $50 from the price of its first-party battery replacement services next month for some phones. Battery replacements for iPhone 6 and newer devices will cost $29 thereafter and will be available at that price through the end of 2018. The company is also working on a software update that will reveal more details of the condition of a device's battery so that iDevice owners can judge whether their batteries are causing performance slowdowns. Apple also vaguely notes that it's always working on ways of improving power-management behavior as devices age.
Although we haven't covered this issue prior to Apple's announcement today, we have been following it (and I'm glad my initial understanding of the problem was apparently correct). The company's response should put to bed the idea that it intentionally slows down devices to spur upgrades to newer iPhones, although one could reasonably conclude that intent doesn't matter if users ultimately felt that a hardware upgrade was necessary after the iOS 10.2.1 update. My feeling is that Apple will be more careful to communicate the full scope of changes like this power-management adjustment in the future, even if they result in mostly-beneficial behavior like fewer sudden shutdowns. We'll see whether that's the case when the next Apple scandal inevitably rolls around.