iOS 12 beta on an old iPhone: How much faster is it?
https://www.cnet.com/news/ios-12-beta-on-an-old-iphone-5s-how-much-faster-is-it/
But one of the most significant changes is performance gains under the hood, especially for older devices.
Apple made some big claims during the WWDC keynote when iOS 12 was first unveiled. Using the example of an iPhone 6 Plus: