What's New in macOS High Sierra: APFS, Metal 2, Photos Improvements, Safari Autoplay Blocking and More

Apple named its next-generation version of the Mac operating system High Sierra because it's designed to improve macOS Sierra through several major under-the-hood updates. While most of what's in High Sierra isn't outwardly visible, there are some refinements to existing features and apps like Safari, Photos, Siri, FaceTime, and more.

We went hands-on with the High Sierra beta to give MacRumors readers a quick idea of what changes and improvements to expect when the software comes out this fall. Check out the video below to see what's new.


Some of the biggest app changes are in Photos, which has a persistent side bar, editing tools for Curves and Selective Color, new filters, options for editing Live Photos, new Memories categories, improved third-party app integration, and improvements to facial recognition, with the People album now synced across all of your devices.

Safari is gaining a new autoplay blocking feature for videos, Intelligent Tracking Prevention to protect your privacy, and options for customizing your browsing experience site-by-site, while Mail improvements mean your messages take up 35 percent less storage space.

Siri has a more natural voice, just like on iOS 11, and can answer more music-related queries. iCloud Drive file sharing has been added, and in High Sierra and iOS 11, all of your iMessage conversations are saved in iCloud, saving more storage space.

When installing High Sierra, it will convert to a new, more modern file system called Apple File System or APFS. APFS is safe, secure, and optimized for modern storage systems like solid-state drives. Features like native encryption, crash protection, and safe document saves are built in, plus it is ultra responsive and will bring performance enhancements to Mac.

APFS is accompanied by High Efficiency Video Encoding (HEVC) which introduces much better video compression compared to H.264 without sacrificing quality. The other major under-the-hood update is Metal 2, which will bring smoother animations to macOS and will provide developers with tools to create incredible apps and games.

Metal 2 includes support for machine learning, external GPUs, and VR content creation, with Apple even providing an external GPU development kit for developers so they can get their apps ready for eGPU support that's coming to consumers this fall. Apple is also working with Valve, Unity, and Unreal to bring VR creation tools to the Mac.

macOS High Sierra will run on all Macs that are capable of running macOS Sierra. For a more detailed overview of what's included in the update, make sure to check out our macOS High Sierra roundup.

Top Rated Comments

true god Avatar
65 months ago
Really excited about APFS.
Score: 40 Votes (Like | Disagree)
djcerla Avatar
65 months ago
The last few months made the Mac great again.
Score: 29 Votes (Like | Disagree)
HobeSoundDarryl Avatar
65 months ago
Wow that reads like it auto-converts HFS to APFS. I wonder how it does that? Create new APFS partition, copy from HFS to APFS, reformat HFS partition to APFS, delete partition to end up with one big APFS partition?

Similarly, I wonder about the relationship of this and Time Capsule? Does Time Capsule remain as is or would it be converted to APFS too?

Can external HFS drive be auto-updated to APFS using the same approach?

Lots of questions.

Edit: lots of people are pointing to this as answers: https://developer.apple.com/videos/play/wwdc2017/715/ Thanks to all.
Score: 17 Votes (Like | Disagree)
CmdrLaForge Avatar
65 months ago
Kind of a Snow Leopard release. Looking forward to this.
Score: 17 Votes (Like | Disagree)
CarlJ Avatar
65 months ago
Can you expand upon this? And if it is clearly better, why do you think Apple didn't adopt it after all? They were working on support for a long time.
I don't know if it's where the OP was going, but one of the things ZFS has that APFS noticeably doesn't, is baked-in error correction and/or checksumming. Having a background task in the kernel slowly (continually or periodically) reading through the entire filesystem and comparing blocks read off the disk with their associated checksums, is huge. If a block goes bad, you find out about it soon, rather than "uh oh", when you really need it. With a filesystem that uses "free" space to store spare copies of blocks, the kernel may be able to recover it on the fly, but even without redundancy, it can flag that the affected file needs to be reloaded from backup (you have those right?) before passing time increases the odds of the backup being overwritten, getting lost, etc. Some sort of systematic kernel-level data integrity checking is the one bit sorely missing from APFS.

(I recall stories of early ZFS builds actually unearthing long-standing 1-in-a-billion errors in device drivers, disk controllers and such - they were occasionally reading back blocks that didn't match the expected checksums, in cases where, say, a device driver managed to not write out an updated copy of a disk block because it got interrupted in an unexpected pattern.)

As to upgrade speeds, APFS was designed so that you can build all the metadata/overhead off in the free space on the disk, and simply point it at/into the existing file content of an HFS+ filesystem (I believe BTRFS has this same feature), and Craig Federighi said during the DaringFireball podcast from WWDC that during the iOS 10.1 and 10.2 upgrades, they actually "migrated" everyone's filesystems to APFS - that is, built the extra metadata/header blocks in the disk's free space - then ran filesystem checks on the result, and sent diagnostic reports back to Apple if anything was amiss, and then discarded the new blocks, leaving everyone with their unharmed HFS+ filesystems. This explains both why the upgrade is so fast, and why it went quite smoothly when iOS 10.3 rolled out.
Score: 16 Votes (Like | Disagree)
newyorksole Avatar
65 months ago
I think it's time to update this 2010 iMac of mine. High Sierra + iMac 2017 = Win

Then will supplement that with iPad 12.9" 2017 + iOS 11.
Score: 11 Votes (Like | Disagree)

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