05.23.2025
Apple's highest-end M3 Ultra chip is currently limited to the Mac Studio, but a new leak has revealed that Apple tested the chip in the MacBook Pro as well. In
In a post today on the Chinese social media platform BiliBili, a user who we are not familiar with said that they found code references to unreleased 14-inch and 16-inch MacBook Pro models with the M3 Ultra chip, in an internal build of iOS 18 running on an iPhone 16 engineering prototype. Specifically, they said that they found J514d and J516d codenames in a file located in the /AppleInternal/Diags/Tests/ folder.
J514 and J516 are the codenames for the 14-inch and 16-inch MacBook Pro models with M3 Pro and M3 Max chips, which were introduced by Apple in October 2023. However, these particular codenames have a "d" suffix, which likely refers to an Ultra chip. For example, the Mac Studio with the M3 Ultra is codenamed J575d.
Apple has never released a MacBook Pro with an Ultra chip, so this is a noteworthy discovery.
Currently, the M3 Ultra is the fastest Mac chip that Apple has ever released. It features up to a 32-core CPU, up to an 80-core GPU, and support for up to 512GB of unified memory, so those could have been MacBook Pro specs in an alternate universe.
Instead, Apple updated the 14-inch and 16-inch MacBook Pro models with M4, M4 Pro, and M4 Max chip options in October last year. Apple most likely decided not to make the M3 Ultra chip available in the MacBook Pro, potentially due to greater thermal and battery life impacts for laptops compared to desktop computers.
With the M4 Max, the MacBook Pro can be configured with up to a 16-core CPU, up to a 40-core GPU, and up to 128GB of unified memory.
All in all, it appears that Apple at least considered MacBook Pro models with the M3 Ultra chip, but it is unlikely that they will ever be released.
Buyer's Guide: MacBook Pro (Neutral)
This article, "iOS 18 Leak Reveals Apple Tested MacBook Pros With M3 Ultra Chip" first appeared on MacRumors.com
Discuss this article in our forums
You may also be interested in this
GM dealers aren’t happy f…
07.10.2023
Earlier this year, GM announced its boneheaded decision to ditch CarPlay in all of its future EVs, opting for a partnership with Google instead. The company has received an incredible
ChatGPT integration in Wh…
02.06.2025
OpenAI announced in December a new integration with WhatsApp, which lets users chat with ChatGPT right from the Meta-owned messaging app. Now the company is taking this integration further, as
Don’t wait to get Prism D…
03.16.2024
Macworld If you’re tired of paying monthly for cloud storage, there might never be a better time to switch. For just 48 hours, new users can get 20TB of lifetime storage for
The AIs are officially ou…
02.23.2024
Image: Alex Parkin / The Verge When you ask an AI bot for an image of the Founding Fathers or a group of German soldiers from 1943, you expect... something.
PSA: You can’t use AirPod…
09.22.2025
Macworld One of the more interesting developments of AirPods Pro 3–one the rumor mill didn’t seem to know about–is that it uses new “foam-infused” eartips. They’re still silicone flanges, but
iOS 18.4 has Apple’s best…
04.03.2025
Apple Podcasts isn’t the dominant force in podcasting that it once was. But if you still get your podcasts from Apple rather than YouTube or another third-party app, there are
Freebeat MorphRover e-bik…
12.18.2023
The Freebeat MorphRover is a fat tire e-bike that works great in rugged environments and can be used indoors as a stationary exercise bike.Freebeat MorphRoverFat-tire bikes have become our favorite
How to Make the iOS 18 Ph…
12.23.2024
With iOS 18, Apple overhauled the Photos app, introducing a new, unified design that did away with the navigation bar and merged everything into a single screen. It marked the

