Apple may have secretly tested an M3 Ultra-powered MacBook Pro, according to a recent leak from early iOS 18 code. Shared via a post on the Chinese platform Bilibili, the discovery includes references to two previously unknown MacBook Pro configurations—J514d and J516d—which appear to hint at an ultra-powerful laptop that never launched.
The current MacBook Pro lineup includes M3, M3 Pro, and M3 Max chips. However, the inclusion of a “d” suffix in the leaked identifiers suggests Apple at least experimented with an “Ultra” variant. This aligns with the naming convention used in other Apple products, such as the Mac Studio with M3 Ultra, internally known as J575d.
Why the M3 Ultra MacBook Pro Likely Didn’t Ship
While Apple’s M3 Ultra chip is one of its most powerful—featuring a 32-core CPU, 80-core GPU, and up to 512GB of unified memory—it’s also extremely power-hungry. The chip is typically reserved for desktops like the Mac Studio due to their ability to handle the required thermal loads.
A MacBook Pro using this chip would likely struggle with heat and battery life. This recalls Apple’s past difficulties with the PowerBook G5, which never shipped due to similar thermal limitations. Given these constraints, Apple may have shelved the M3 Ultra laptop during internal testing.
How Reliable Is the Leak?
The leak reportedly came from early iOS 18 software found on a prototype iPhone 16. These internal builds often contain references to experimental hardware, some of which never see a public release. Though not confirmed, the source also correctly referenced other prototype Apple devices and tools, lending the claim partial credibility.
What This Means for Apple’s Future
The discovery doesn’t confirm an upcoming release but does reveal Apple’s interest in pushing the limits of its laptop performance. As macOS and iOS development continues, further code leaks could offer more clues about Apple’s hardware roadmap. For now, the M3 Ultra MacBook Pro remains an intriguing “what if.”
