Updated Notification Center brings notifications and widgets together in one view.Support for pinning favorite menus from Control Center to the menu bar.Additional controls appear when you click to expand Control Center menus.Control Center puts your favorite menus and controls in one handy place in the menu bar so you can quickly adjust settings as you work.Refreshed system sounds include the boot chime and sounds for transferring files, moving items to the trash, locking files, and more.Updated menu bar features wider spacing and a new translucent material that becomes more vibrant when you interact with it.New design for apps makes it easier to focus on your content and take action with space efficient toolbars and full height sidebars.To see which model you have, click the Apple icon in your menu bar and choose About This Mac. Get even more transparency around your privacy.Ĭhances are, your Mac can run macOS Big Sur Discover new features for Maps and Messages. macOS Big Sur brings a refined new design that gives you even more of the things you love about Mac. If you start up from a different disk, the setting on that disk, or the hardware default, will take effect.MacOS Big Sur elevates the most advanced desktop operating system in the world to a new level of power and beauty. Note: This setting is stored in the /Library/Preferences/SystemConfiguration/ file and will take effect every time you start up from this disk. Sudo systemsetup -setkernelbootarchitecture i386

To select the 32-bit kernel for the current startup disk, use the following command in Terminal: Sudo systemsetup -setkernelbootarchitecture x86_64 To select the 64-bit kernel for the current startup disk, use the following command in Terminal: Your Mac will revert to the default kernel the next time you reboot it.

If your Mac uses the 64-bit kernel by default, you can start up with the 32-bit kernel by holding the 3 and 2 keys during startup. If your Mac uses the 32-bit kernel by default, but supports the 64-bit kernel, you can start up using the 64-bit kernel by holding the 6 and 4 keys during startup.

32bit mode lets you also execute 64bit apps. Lion still has both kernels, so yes you can run in 32 or 64bit mode.

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