Samsung’s One UI 8.5 Beta 4 (firmware ZZAB) arrives with a refreshed Linux kernel, a new Direct Voicemail shortcut in the Phone app, and significant Bixby AI enhancements. Targeted for the Galaxy S25 series and other compatible devices, the update also includes stability patches that improve overall performance and power management while preparing the platform for upcoming Android 15 features.
Key Features in the ZZAB Build
- Kernel refresh – Updated Linux kernel delivers performance optimisations, better power efficiency, and broader hardware support.
- Direct Voicemail – Users can open their voicemail inbox directly from the Phone app, eliminating carrier‑specific navigation steps.
- Bixby AI boost – Faster voice recognition, more context‑aware suggestions, and tighter integration with Samsung services.
- Stability patches – Under‑the‑hood fixes address UI glitches, camera stability, and connectivity issues.
Why the Kernel Update Matters
The kernel is the core of Android’s operating system. By upgrading it in Beta 4, Samsung fine‑tunes CPU scheduling, memory management, and driver compatibility across the Galaxy S25 lineup and other eligible devices. This groundwork helps ensure smoother multitasking, reduced battery drain, and readiness for future hardware features.
Impact for Users
End users will notice two immediate, user‑facing improvements:
- Direct Voicemail streamlines access to voice messages, saving taps and time, especially on carriers with complex voicemail menus.
- Bixby enhancements make the assistant more responsive and useful for tasks such as SmartThings automation, camera controls, and quick replies.
Developer Considerations
Developers should test native code and custom ROM components against the new kernel, as API behavior and driver interfaces may shift. Monitoring performance metrics during the beta phase can help identify regressions before the final One UI 8.5 release.
Rollout Timeline
The beta is expected to appear in the Settings → Software update menu for devices enrolled in Samsung’s beta program within the coming week. Historically, Samsung limits beta distribution to flagship and upper‑midrange models that meet specific hardware thresholds.
Future Outlook
One UI 8.5 Beta 4 signals Samsung’s continued focus on refining core performance while adding practical user features. As the beta expands, the community will gather real‑world data on speed, battery life, and Bixby’s new capabilities, shaping the final release slated for later this quarter.
