If you’re among the growing number of users hoping to soon see updated versions of the MacBook Pro with the new M5 chips, today’s macOS 26.3 RC brings great news. Here are the details.
Reference M5 Max and M5 Ultra
As he states MacRumorstoday’s macOS 26.3 Release Candidate build contains references to what are very likely two new M5 chips for upcoming MacBook Pro updates.
More specifically, macOS 26.3 RC contains internal references to two new SoC IDs, T6051 and T6052, which are denoted by platform codes H17C and H17D.
To make sense of these codes, here are the SoC IDs and platform codes that Apple has used for all other Apple Silicon M-series chips so far:
| Chip | SoC ID | Platform code |
|---|---|---|
| M1 | T8103 | H13G |
| M1 Pro | T6000 | H13J or H13S |
| M1 Max | T6001 | H13J or H13C |
| M1 Ultra | T6002 | H13J or H13D |
| M2 | T8112 | H14G |
| M2 Pro | T6020 | H14S |
| M2 Max | T6021 | H14C |
| M2 Ultra | T6022 | H14D |
| M3 | T8122 | H15G |
| M3 Pro | T6030 | H15S |
| M3 Max | T6031 or T6034 | H15C or H15M |
| M3 Ultra | T6032 | H15D |
| M4 | T8132 | H16G |
| M4 Pro | T6040 | H16S |
| M4 Max | T6041 | H16C |
| M5 | T8142 | H17G |
Based on this standard, it is likely that IDs T6051/H17C refer to the upcoming M5 Max chip, while IDs T6052/H17D refer to the M5 Ultra.
Interestingly, there doesn’t seem to be any reference yet to the M5 Pro chip (which should carry T6050/H17S identifiers), although in theory at least the RC should be the exact same build that will be revealed publicly when the release candidate becomes the final release.
We’ll likely find out sooner rather than later what this means for the release timeline of the next MacBook Pros. Bloomberg recently announced that the new models are “planned for the macOS 26.3 software cycle.”
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