Apple’s base iPhone 18 and iPhone 18e will not support two significant iOS 27 Apple Intelligence features despite receiving a RAM upgrade to 9GB, because the advanced on-device model powering those capabilities requires a minimum of 12GB of unified memory. The missing features are the ability to customize Siri’s voice expressiveness and pace, and a major boost in accuracy for speech-to-text dictation across the system.
As shared by analyst Ming-Chi Kuo on X, the 1GB increase from the iPhone 17’s 8GB of RAM ensures that Apple Intelligence features run smoothly on the lower-end models, but it falls short of the threshold required for customizable Siri voices and advanced dictation. Apple’s higher-end models, the iPhone 18 Pro, iPhone 18 Pro Max, and the forthcoming foldable iPhone Ultra, will each retain 12GB of RAM and gain access to both features. The second-generation iPhone Air is also expected to include 12GB of RAM.
The exclusion represents a tangible trade-off as Apple manages component constraints. During its WWDC 2026 keynote in early June, the company highlighted customizable Siri voice expressiveness and improved dictation accuracy as marquee features of its next-generation Apple Intelligence capabilities. These tools directly impact the user experience for anyone relying on voice interaction or dictation workflows, yet they will remain unavailable to customers purchasing the base iPhone 18 models when they launch in March 2027.
Apple Intelligence features broadly are already restricted to iPhone 15 Pro and newer, a limitation the company justified based on processing requirements. The RAM constraint now introduces an additional tier of exclusivity within the iPhone 18 lineup itself. Unlike previous generational upgrades where base and Pro models received most of the same capabilities, iOS 27 marks a shift toward memory as a determinant of AI feature access.
The timing of this announcement, three weeks after Apple’s WWDC keynote, reflects ongoing memory supply pressures affecting the company’s broader product strategy. RAM and NAND storage chips are currently expensive due to a supply shortage, a constraint that has prompted Apple to raise prices across more than a dozen products. This component scarcity appears to have influenced the RAM allocation across the iPhone 18 lineup, preventing Apple from equipping even the base models with 12GB despite earlier industry signals that standard models would eventually gain access to higher memory tiers.
The 9GB figure represents a compromise between cost management and maintaining a minimum threshold for core Apple Intelligence functionality. Apple has calculated that 9GB is sufficient for existing on-device models to function reliably, while reserving the advanced model and its voice customization layer for the more expensive tiers where customers expect premium features and where Apple can more easily absorb component costs.
iOS 27 is currently in developer beta and will enter public beta in July 2026 ahead of its September release alongside the iPhone 18 Pro, iPhone 18 Pro Max, and iPhone Ultra. The iPhone 18 and iPhone 18e standard models are not scheduled to arrive until March 2027, meaning this RAM limitation will become visible to testers during the public beta phase months before those devices ship. By then, customers evaluating the lower-end models will have a clear understanding of which iOS 27 features they are purchasing away from.
