Apple’s iOS 26.3 RC Update Reportedly Contains References to Anticipated M5 Max, M5 Ultra Chips

Apple has recently seeded the release candidate (RC) versions of iOS 26.3 and iPadOS 26.3 to developers for testing. The iOS 26.3 RC reportedly includes references to two unreleased chips from Apple's upcoming M5 lineup. The code reportedly offers insights about the M5 Max chip and hints at the M5 Ultra, which could arrive with a refreshed Mac Studio. Apple is likely to launch new MacBook Pro models soon, powered by these next-generation chips alongside macOS 26.3.

iOS 26.3 Code Hints at M5 Max and M5 Ultra Chips

X user Nicolás Alvare spotted references to Apple's unreleased M5 chips in the iOS 26.3 release candidate (via MacRumors). The latest release for beta testers mentions two new system-on-chip (SoC) models — T6051 and T6052. These are reportedly linked to the platform names H17C and H17D. The '17' in the names is said to reference the M5 chip generation.

If we look at Apple's past naming patterns, the H17C chip is likely the M5 Max, while H17D could be the M5 Ultra. Apple has previously used the letter 'C' for Max chips and 'D' for Ultra chips. G is used for standard chips, and 'S' is used for Pro chips.

The code doesn't include a reference to the T6050 or H17S, according to the report, which would normally refer to the M5 Pro chip. It's uncertain if Apple has changed its internal chip naming or if the M5 Pro has not been added to the code yet.

Apple is expected to launch updated MacBook Pro models with new M5-series chips alongside macOS 26.3. The launch could take place either in February or March 2026. The company is rumoured to launch an M5 Ultra-powered Mac Studio.

Meanwhile, the stable versions of iOS 26.3 and macOS 26.3 are expected to land on eligible iPhone and Mac models later this month. The update is expected to improve the RCS messaging capabilities with Android phones. It is likely to be released alongside iPadOS 26.3, watchOS 26.3 and tvOS 26.3.