Massive iPhone Upgrade Coming This Year But These Devices Will Miss Out

Apple is planning a major AI overhaul in iOS 18, thanks to a feature set called "Apple Intelligence." However, these new features will not work on older iPhones, even if they do appear on the new operating system's device compatibility list.

Apple's initial AI roadmap for iOS 18 is coming in two parts: Basic AI features that will be processed on-device, and more advanced capabilities that will require communication with Apple's servers.

At the heart of many of the new Apple Intelligence features is a redesigned Siri. To that end, Apple engineers have had to rearchitect ‌Siri‌'s underlying software using large language models (LLMs), the algorithm that underpins generative AI.

Apple says this will allow Siri to do things like open specific documents, organize notes in folders, delete an email, summarize an article, email a web link, and more. In fact, Apple plans to use AI to analyze what people are doing on their devices to automatically enable these‌ features.

Apple's own LLM is expected to handle what are deemed basic AI tasks, and it will be entirely on-device. In other words, the model is powered by the iPhone's processor, rather than in the cloud. It's not clear what the criteria for a basic task will be, but the LLM is said to include code that determines if a request can be processed on device or requires Apple's servers.

Apple has revealed that the on-device AI capabilities will require an iPhone 15 Pro or later to work.
That said, iOS 18 will be compatible with the same iPhone models as iOS 17. In other words, expect the following iPhone models to run iOS 18, but lack support for some of Apple's on-device AI features:

iPadOS 18 and macOS 15 will share many of the same AI features, but it's important to note that Macs and iPads will need at least an M1 chip to power the on-device AI capabilities. In other words, Apple silicon Macs are the requirement for on-device AI in macOS 15, which rules out Intel Macs. In the same way, anything older than the fifth-generation iPad Pro will not support on-device AI features in iPadOS 18.

It's worth noting that (non-supported) standard iPhone 15 models have 6GB of RAM, while the supported Pro models have 8GB of RAM. Likewise, all Apple Silicon iPads and Macs come with a minimum of 8GB. Even when scaled back for narrow use cases, LLMs require a lot of working memory due to the sheer number of parameters involved, so it looks like this is where Apple is coming up against the hardware limitations of its own devices.