Another WWDC has passed by, and this time it is bittersweet, as Apple has officially declared macOS Tahoe 26 to be the last version to support Intel Macs. Nevertheless, Apple has dropped additional Intel Macs from the support list, leaving only 6 models capable of running the last version of macOS to support Intel.

As the OS has been in developer beta for a few weeks now, we've compiled a list of challenges the patcher will need to overcome for this fall. This list will likely expand as we determine more issues with older systems.

• Dropped Models
• T2 Challenge
• iMac19,x Audio Support
• Fusion Drive Support
• FileVault
• Graphics Support
  • Metal 31001
    • Intel Broadwell and Skylake
    • AMD legacy GCN, and modern GCN on non-AVX2.0
  • Metal 3802
    • Intel Ivy Bridge and Haswell
    • Nvidia Kepler
  • Non-Metal
    • Intel Iron Lake and Sandy Bridge
    • AMD TeraScale
    • Nvidia Tesla and Web Drivers
• General patches needing updates:
  • Wireless
  • T1 Chip
  • USB
• Overall timeline for support

Dropped Models

With this release, we have several models dropped, with the last T2-less Mac being dropped.

iMac19,1:        iMac (Retina 5K, 27-inch, 2019)
iMac19,2:        iMac (Retina 4K, 21.5-inch, 2019)
iMacPro1,1:      iMac Pro (2017)
MacBookAir9,1:   MacBook Air (Retina, 13-inch, 2020)
Macmini8,1:      Mac mini (2018)
MacBookPro15,x:  MacBook Pro (13/15-inch, 2019/2019)
MacBookPro16,3:  MacBook Pro (13-inch, 2020, Two Thunderbolt 3 ports)

Currently, besides T2 issues, the only known limitation with these models is audio support for iMac19,x. Graphics drivers have not been dropped.

T2 Challenge

As seen with MacBookAir8,x and macOS Sequoia, T2 machines have panic issues when booting the OS through OpenCorePkg. Although we have made some progress on this issue, panics are still occurring and there is still a significant amount of development work to do before T2 machines may even get to the install screen. We cannot provide any estimate on when T2 machines will be supported.

iMac19,x Audio Support

With beta 2, Apple has removed AppleHDA.kext, responsible for analog audio support, as all remaining supported Macs route audio through the T2. Restoring this kext should solve the problem but remains to be tested.

Fusion Drive Support

Apple no longer supports Fusion Drives, and has subsequently removed support for them from macOS; Fusion Drives appear as split volumes. It is unknown whether support can be restored.

FileVault

There have been reports of FileVault being turned on automatically with the installation of Tahoe, leading to issues with volume decryption. This is another casualty of the OS only supporting T2 Macs (which handle FileVault through the T2). This should be fixed with using apfs.efi from Sequoia, but remains to be tested.

Graphics Support

With macOS Tahoe, Apple has introduced yet another graphics redesign, Liquid Glass. Despite this major design change, thanks to the hard work of @covasedu and @asentientbot, we have some initial, but promising, results:

Metal 31001	Metal 3802	Non-Metal

Due to the nature of how non-Metal graphics support works, the downgrades involved will not allow for Liquid Glass to be supported on these cards. Instead, workarounds for a usable interface will be implemented.

General patches needing updates

So far, the following patches have been identified as being broken either partially or entirely. This will require additional work to properly identify issues and solutions:

• Wireless
• T1 Chip
• USB

Overall timeline for support

As with every year, we cannot promise when support will be added. As a rough estimate, we hope for the upcoming winter with OpenCore Legacy Patcher v3.0.0. The additional dropped T2 models are a significant challenge and will require extensive time and research.