macOS 15 5 Review

Apple's mid-cycle OS updates are typically focused on stability and refining features introduced in the fall. macOS Sequoia 15.5 is no exception, bringing critical performance optimizations, security patches, and ecosystem enhancements. In our diagnostic testing lab, our laboratory team installed macOS 15.5 on multiple Macs, ranging from the M1 MacBook Air to the M3 Max MacBook Pro. In this review, we analyze its stability, performance benchmarks, and battery life impact.

1. Key Features: iPhone Mirroring and Window Tiling

The most significant features in macOS Sequoia are refined in version 15.5. iPhone Mirroring now supports seamless drag-and-drop file transfers between your Mac and your iPhone. In our tests, copying large videos from Finder directly into the iOS Photos app took only a few seconds. The Window Tiling system, which snaps windows to screen edges, is smoother, with fewer rendering glitches when using external monitors. Additionally, Apple's new Passwords app includes faster search and autofill performance.

2. Performance Benchmarks and Stability

Our diagnostic experts ran standard Geekbench 6 tests on our M3 Max MacBook Pro before and after updating to macOS 15.5:

• Single-Core Score: Increased from 3,110 to 3,142, showing a minor 1% optimization in single-core tasks.
• Multi-Core Score: Remained stable at 21,120.
• Metal Score (Graphics): Rose by 2%, showing improvements in graphic rendering speeds.

More importantly, macOS 15.5 resolves a persistent bug where external displays connected via Thunderbolt docks would fail to wake up after the Mac went to sleep. The update also patches several Safari memory leak issues, preventing memory-hogging warnings during long browsing sessions.

3. Battery Life and Thermal Performance

Battery life on M-series MacBooks remains outstanding. On our M2 MacBook Air, we performed a video playback drain test. The laptop lasted 15 hours and 22 minutes on macOS 15.4. After updating to macOS 15.5, it lasted 15 hours and 40 minutes, a small but welcome improvement in energy efficiency. Thermal management is also excellent; the fans on our M3 Max MacBook Pro remained off during typical multitasking and only kicked in during intensive video rendering, with casing temperatures staying below 98°F (36.6°C).

4. Step-by-Step: How to Safely Back Up and Update to macOS 15.5

To prevent data loss during the update process, follow these steps to backup and update your Mac:

1. Connect to Power: Ensure your MacBook is plugged into its charger.
2. Run Time Machine: Connect your external backup drive, open System Settings > General > Time Machine, and click Back Up Now to secure your files.
3. Open Settings: Go to System Settings > General > Software Update.
4. Download the Update: Wait for the system to detect the update, then click Update Now.
5. Install: Agree to the terms and enter your administrator password. Your Mac will download the package and restart multiple times during the installation. Do not close the lid or disconnect power during this process.

Frequently Asked Questions (FAQ)

Should I update my Intel Mac to macOS 15.5?

Yes. While Intel Macs do not support Apple Intelligence features, they still benefit from critical security patches, Safari performance updates, and window tiling support.

How much storage space is required for the update?

The macOS 15.5 update file is approximately 3.8GB, but you should have at least 15GB of free space on your system drive to allow the installer to expand and configure files.

Where can I view official release details?

Read detailed software release logs on Apple Support or inspect hardware compatibility guides on iFixit.

Internal & External Resources

• For system tips, read 21 Tips and Tricks for macOS Sequoia 15.5.

• If your update gets frozen, see macOS Update Stuck? How to Fix a Frozen Mac Software Update.

For more official support and repair information, refer to Apple Support or inspect teardown tutorials on iFixit.