macOS 27 workaround blocks AI model downloads and frees storage

The problem

Apple’s macOS 27 installs the model files that power Apple Intelligence and the new Siri, and users report that they arrive even on machines where the assistant is switched off. On storage-constrained Macs, particularly models with 256 GB drives, those assets can occupy tens of gigabytes. A closely followed thread in the r/MacOSBeta community, updated for the public release of macOS 27, now documents which workarounds actually hold.

Two settings that stop the downloads

The author of the post, u/animorphreligion, lists two verified methods and advises picking one. The first is a Siri language mismatch: turn Siri off, then choose a language that does not match the system language and, preferably, is not supported by it. The second is the original workaround, enabling Low Data Mode for the network in System Settings, but the author now recommends it only as a last resort, because it also blocks macOS updates and can introduce syncing problems.

The order matters: the setting has to be applied before the model files are deleted, otherwise the system downloads them again.

Removing the model files

With one of those settings in place, the assets can be removed from Recovery mode. The user shuts the Mac down, holds the power or Touch ID button until the startup options appear, chooses Options, mounts the Data partition in Disk Utility and runs two commands in Terminal from the directory /Volumes/Data/System/Library/AssetsV2: first removing the Foundation Models assets whose names begin with com_apple_MobileAsset_UAF_FM, then, to clear partial downloads, the downloadDir folder.

The post stresses that the procedure is safe, since system integrity protection does not need to be disabled and only the language-model assets are touched, and that it is easily reversed by changing the setting back.

What users report

Replies to the thread are mixed. Some users say the models reappear after a reboot and that a persistent solution is still missing, while others report that Low Data Mode alone stops the downloads and that they regained 20 to 25 GB of disk space. Commenters also note that with the assets gone, AI features in Photos display a download error instead of an unrelated message, and that a feedback report asking Apple to make the feature opt-in was closed as “works as currently designed”. The author adds that tracing the download process required a privileged network proxy, because the system hides which service is fetching the files.