System
Support for Apple silicon
macOS Big Sur is the first release of macOS for Macs powered by
Apple-designed ARM64-based processors, a key part of the transition
from Intel x86-64-based processors. The chip mentioned in demo videos,
and used in the Developer Transition Kit, is the A12Z Bionic. On
November 10, 2020, Apple announced the first Mac Apple silicon chip,
the Apple M1, in the Late 2020 Mac Mini, MacBook Air, and MacBook Pro.
Apple has said that it will support Intel Macs "for years to come",
and most software that has not been ported to run on ARM Macs can use
Rosetta 2, an update of a compatibility mechanism originally developed
for the PowerPC-to-Intel x86 transition. Likewise, Apple also
introduced an updated universal binary format, Universal 2, which
allows developers to package their applications so that they can run
natively on both ARM64 and x86-64 processors.
Support for iOS and iPadOS applications
On Macs based on Apple silicon, macOS Big Sur can run iOS and iPadOS
applications natively and without any modifications needed from
developers, aside from allowing the app to be available on the Mac App
Store. The first Macs with this capability are those that use the
Apple M1 SoC (system on a chip).
Time Machine overhaul
Time Machine, the backup mechanism introduced back in Mac OS X 10.5
Leopard, has been overhauled to utilize the APFS file system
(introduced in MacOS High Sierra) instead of the outdated HFS+.
Specifically, the new version of Time Machine makes use of APFS's
snapshot technology. According to Apple, this enables "faster, more
compact, and more reliable backups" than were possible previously with
HFS+-formatted backup destinations. An independent evaluation of this
claim found that Time Machine on macOS 11 in conjunction with APFS was
2.75-fold faster upon initial local backup and 4-fold faster upon
subsequent backups relative to macOS 10.15's Time Machine
implementation using HFS+. A more modest yet nevertheless significant
advantage was noted as well for backups to network-attached disks.
New local (i.e. USB- or Thunderbolt-connected) and network-connected
Time Machine backup destinations are formatted as APFS by default,
though Time Machine can continue backing up to existing HFS+ backup
volumes. There is no option to convert existing, HFS+-based backups to
APFS; instead, users who want to benefit from the advantages of the
new, APFS-based implementation of Time Machine need to start with a
fresh volume.
In the new version of Time Machine, encryption appears to be required
(instead of merely optional) for local disks, but it remains elective
for networked volumes.
It is no longer possible to restore the whole system using a Time
Machine backup, as the signed system volume is not backed up. Non-core
applications and user data can be restored in full using Migration
Assistant, preceded by a system reinstall if necessary.
Spotlight
Spotlight, the file system indexing-and-search mechanism introduced in
Mac OS X 10.4 Tiger, is faster and the interface has been refined.
Spotlight is now the default search mechanism in Safari, Pages, and
Keynote.
Signed system volume
The system volume containing the core operating system is
cryptographically signed. Apple indicates this is a security measure
to prevent malicious tampering. This includes adding an SHA-256 hash
for every file on the system volume, preventing changes from
third-party entities and the end user.
Software updates
Software updates can begin in the background before a restart, thus
requiring less downtime to complete. Because system files are
cryptographically signed, the update software can rely on them being
in precise locations, thus permitting them to be effectively updated
in place.
Encryption
macOS Big Sur supports encryption at the file level. Earlier versions
of macOS (10.15 Catalina and older) supported encryption only at the
level of entire volumes. As of June 2020, this capability is known to
be compatible with Macs based on Apple silicon; it is unclear whether
it is compatible with Intel-based Macs.
Application features
Safari
Big Sur includes Safari 14, which was also released for macOS Catalina
and macOS Mojave on September 16, 2020. Safari 14 includes features
such as a new home page in which users can customize what features are
visible in addition to being able to set a custom wallpaper. It also
allows the viewer to preview a page and favicon before visiting it.
Safari 14 also includes built-in web page translations in English,
Spanish, German, French, Russian, Chinese and Portuguese as well as
support for 4K HDR content from Netflix on Macs with an Apple T2 chip,
although none of these were made available for macOS Catalina and
Mojave.
Privacy features such as iCloud Keychain (which notifies users of
compromised passwords), extension privacy management and Privacy
Report (which monitors privacy trackers and further increases Safari's
security) were added for Safari 14. Users were now also able to import
password from Google's Chrome browser in addition to being notified of
compromised passwords.
Safari 14 also supports WebExtensions API, the WebP image format as
well as VP9 decoding, the latter of which allows for the playback of
4K and HDR content from YouTube. In addition, it allowed for better
performance and power efficiency.
Safari 14 ended support for Adobe Flash Player in September, three
months prior to its end-of-life on December 31, 2020.
Messages
The Messages app was rewritten to be based upon Apple's Catalyst
technology to enable it to have feature parity with its iOS
counterpart. The new version of the app included a refined design as
well as the ability to pin up to nine conversations that can sync
across iOS, iPadOS and macOS. Users were also now allowed to search
for messages and share their names and photos. Photo thumbnails could
now also be used for group chats on the app.
In addition, users could mention contacts by putting the @ symbol in
front of their name. They were also able to reply to specific
messages. Memojis, 3d avatars were also made available on Messages. On
Messages, users could now select photos based on parameters.
In India, text message effects were added when users sent certain
texts (e.g., texting "Happy Holi" will result in users seeing
effects).
Mac App Store
Refinements and new features of the Mac App Store include:
-
A new "nutrition label" section dedicated to the data and
information an app collects, also featured in the iOS App Store
- A new extensions category for Safari
-
Third party Notification Center widgets, similar to those also added
in iOS and iPadOS 14.
-
The ability to share in-app purchases and subscriptions on the Mac
via iCloud Family Sharing
Notes
Changes to the Notes app include:
- A collapsible pinned section
- Quick text style and formatting options
- Scanning enhancements
Photos
Changes to the Photos app:
- New editing capabilities
- Improved Retouch tool
- New zooming feature in views
Maps
New features and changes to the Maps app are as follows:
-
"Look Around" interactive street-level 360° panoramas, first
implemented in the iOS 13 version of Maps, have been incorporated
into the macOS version of Maps.
- Availability of directions for cyclists.
-
Electric vehicle routing, based on proximity to charging stations
and monitoring of battery levels (on selected car models).
- Guides for exploring new places.
Voice Memos
These are the new features and changes made to Voice Memos:
-
A file structure has been implemented to allow organization of
recordings in folders
-
Recordings can be marked as Favorites for easier subsequent access
-
Smart Folders automatically group Apple Watch recordings, recently
deleted recordings, and Favorites
-
Audio can be enhanced to reduce background noise and room reverb
