Apple’s iOS 26.3 release candidate quietly points to new Apple Silicon chips that sit inside the M5 family. The code includes two unreleased system-on-a-chip models that line up with what Apple usually ships in its high-end MacBook Pro and desktop Macs. As a result, this early software leak now offers one of the clearest signs yet that Apple is preparing more powerful M5 machines.
In a new finding, Nicolás Alvarez shared the discovery with MacRumors after spotting the chip references inside the iOS 26.3 RC files.
The software mentions two new chip identifiers, T6051 and T6052. These also carry platform names H17C and H17D. Apple uses this internal naming system to tag each Apple Silicon generation. The number 17 links directly to the M5 family, since the base M5 chip already carries the H17G label.
Over the years, Apple has followed a clear pattern with these letters. The C label stands for Max chips, while the D label stands for Ultra chips. Apple also uses S for Pro chips and G for standard versions. This makes the meaning of these two new entries easy to read.
What the iOS 26.3 code shows
Here is what the beta reveals:
- T6051 with H17C points to an M5 Max chip
- T6052 with H17D points to an M5 Ultra chip
- T6050 with H17S, which would be the M5 Pro, does not appear in the code
Apple has used this same structure for years. M1 Max, M2 Max, M3 Max, and M4 Max all carried a C tag. The Ultra chips followed the D tag with M1 Ultra, M2 Ultra, and M3 Ultra. Apple skipped an M4 Ultra, so this M5 Ultra would mark its return.
The missing M5 Pro makes the situation unusual. It raises three options. Apple has not added it to this build yet. Apple changed its naming system, or Apple plans to ship MacBook Pro models that only use the Max and Ultra chips.
We only see references to the M5 Max and M5 Ultra chips, and the reason behind this remains unclear. That uncertainty adds weight to recent talk about high-end M5 MacBook Pro models arriving soon, along with a future Mac Studio that uses the M5 Ultra.
