Apple said that iOS 9 will bring performance improvements to all iOS devices, including older models that were slowed down by the iOS 8 update. However, when all said and done, it turned out that iOS 9 wasn’t able to dramatically increase overall speed, no matter how much optimization it underwent.
Various early tests showed last September the initial version of iOS 9 lagging behind the latest stable version of iOS 8. Since then, Apple released a slew of minor update, with the latest one significantly improving overall user experience on old devices such as the iPhone 4s and iPhone 5.
New comparisons videos show that iOS 9.2.1, which was released only a few days ago, can be as fast, and even faster than iOS 8.4.1 when running on older iPhones. According to testing done by YouTube channel iAppleBytes, even boot times are speedier when running iOS 9.2.1 on the iPhone 5s, the first iPhone to pack a 64-bit processor.
Apple has recently been targeted with a class action suit that alleges the company misled customers into thinking iOS 9 will offer a smoother, speedier experience than iOS 8 on old devices while knowing the update will lead to a drop in performance. But that’s probably not why Apple is “fixing” iOS 9 for older handsets and tablets. The company is likely more interested in boosting its iOS 9 stats, and that means getting more iPhone owners to upgrade to the latest iOS version, including those people who still use iPhone 4s and iPhone 5.
One other reason to update to iOS 9.2.1 is the fact that Apple patched a software issue in this release, one that wasn’t fixed for nearly three years.
An extensive video showing the performance gains of iOS 9.2.1 follow below. Before you get all excited about iOS 9.2.1 breathing new life into your aging iOS device, you should also remember that upgrading to iOS 9.2.1 is a one-way trip. You won’t be able to downgrade to iOS 8.4.1 after you make the jump, at least not officially.