iOS 27 landed this week carrying a real overhaul to Apple Intelligence, not just a minor update. Siri AI alone represents a massive leap over what came before, capable enough that 9to5Mac recently compiled a list running past 100 different tasks it can now handle. Given how ambitious these new features are, it’s honestly a little surprising most iPhones didn’t need any extra storage at all to run them. That 8GB baseline held steady for the majority of devices.
Eight gigabytes used to cover it. On a handful of newer iPhones now, that number just climbed to 14GB, and Apple’s own support documentation confirms it.
Not every phone got off that easy, though. A specific group of iPhones needs nearly double the space, 14GB instead of 8GB, just to unlock the full set of AI features in iOS 27. That list includes the iPhone 18 Pro, iPhone 18 Pro Max, iPhone Duo, iPhone 17 Pro, iPhone 17 Pro Max, and the iPhone Air. The list also extends to:
- iPad models with M4 and later and at least 12GB of unified memory
- Mac models with M3 and later and at least 12GB of unified memory
- Apple Vision Pro (M5)
(Presumably, this storage requirement will apply to the upcoming iPhone Duo when it launches)
Why these specific models? Two capabilities, and only these devices get them. First, Siri AI can adjust its own voice, tweaking expressivity and pacing in ways the standard version can’t. Second, dictation accuracy gets a real boost on these phones compared to everywhere else. Both features lean on a beefier on-device AI model, and that model simply takes up more room than the standard one running on every other iPhone.
Everything outside that specific list stays right where it’s always been. Standard iPhones still only need 8GB free to run iOS 27’s AI features, no change there at all.
It’s a fair trade-off when you think about it. More capable AI features generally mean heavier models, and heavier models need more space to actually live on your device. Anyone planning to update a supported iPhone to iOS 27 should probably do a quick storage check first, just to make sure there’s enough breathing room before diving into everything the update has to offer.
