Apple’s macOS High Sierra (aka macOS 10.13) is the newest version of Apple’s Mac and MacBook operating system. It launched on 25 September 2017 bringing new core technologies, including an entirely new file system (APFS), virtual reality related features, and refinements to apps such as Photos and Mail.

Over the months that followed the introduction, a number of software updates have been issued to introduce new features and to fix issues and vulnerabilities – something that has unfortunately plagued this version of the Mac operating system, so much so that Apple has said it will focus on stability in the next version of macOS.

The latest update to be issued to High Sierra is version 10.13.4. We’ll tell you more about that update below. Moving swiftly on, the 10.13.5 developer beta is already out…

In this article we’ve got everything you need to know about High Sierra including details of the issues, problems and security vulnerabilities that have been discovered, as well as details about the latest beta versions of High Sierra, and the upcoming features Apple is adding to the operating system that all users will eventually see in the next update to High Sierra.

Read on to find out what the latest version of High Sierra is, and whether you should go ahead and download it. If you would like to find out about the next version of the Mac operating system – macOS 10.14 – you can read about that here

Below we will run through the various updates to High Sierra that have been issued since the macOS software was released, as well as the beta and public beta versions that have been issued. (A security update was issued on 22 January 2019 – more information here: How to stop your iPhone, iPad or Mac getting hacked)

First up, we’ll look at some of the features that were promised for High Sierra but haven’t yet arrived…

New features coming to MacOS High Sierra

Not every new feature that Apple indicated would arrive in High Sierra has made it through the beta testing process yet. While the company may decide to wait until the next big update to macOS (macOS 10.14) it might still roll these features out in an update to macOS High Sierra.

Thanks to the latest beta version, we already know that one feature is likely to make an appearance on MacOS (and iOS 11) soon – Messages on iCloud should mean that your messages are better synced across all your devices.

Another feature that has been missing is APFS for Fusion Drives. It’s nearly a year since Apple announced High Sierra and with it the advent of a new file system – APFS, and yet APFS still doesn’t work with Fusion Drives (which combine a hard drive with a fast flash drive).

Well it looks like that could be about to change very soon. Apple’s Craig Federighi has responded to a Mac user who asked whether APFS was ever going to make it to the Fusion Drive, saying “We intend to address this question very soon…” The email was forwarded to, and verified by, MacRumors.

Whether this will arrive in the form of an update to High Sierra, or as part of the next version of the Mac operating system (macOS 10.14) remains to be seen, but “very soon” could indicate that the company will be talking about APFT as WWDC in June.

MacOS High Sierra 10.13.6 beta

In an unusual move, Apple has already issued a beta version of the next major point update to High Sierra – despite not having issued High Sierra 10.13.5 yet.

It’s not known what the beta currently includes, but it’s likely to be bug fixes.

There may also be new emoji coming soon, apparently, Apple is planning to introduce 13 new emoji to represent people with disabilities. However, the company may hold these back to a future update.

What is the latest version of macOS High Sierra?

Below we wll run through each of the versions of MacOS High Sierra that have been issued, explaining what new features and fixes arrived with them.

To find out which version of macOS you are running click on the Apple icon on the left side of your screen, and About this Mac.

If you want to update to a newer version, click on Software Update to be taken to the Mac App Store. Beware sometimes updates can take a good half hour, so make sure you have the time to spare! (If you want to decide whether or not the upgrade to High Sierra is worth it, check out our Sierra vs High Sierra comparison review.)

MacOS High Sierra 10.13.5

Apple made the High Sierra 10.13.5 available on 1 June. The accompanying iOS 11 release – iOS 11.4 – had already been pushed out to iPhones and iPads, and with it the ability to turn on Messages in iCloud. Now the same capabilities are available for macOS.

Read about how to turn on Messages on iCloud so that you can keep all your messages in sync across all your devices, save space on your iPhone, and keep all your messages and attachments backed up.

Security Update 2018-001 for macOS 10.13.4

macOS 10.13.4 received an update on 25 April. Security Update 2018-001 for macOS 10.13.4 addresses the following security vulnerabilities:

• An issue where an application may be able to gain elevated privileges due to a memory corruption issue.
• An issue where processing a maliciously crafted text message may lead to UI spoofing. This was related to the handling of spoofed URLs.

MacOS High Sierra 10.13.4

macOS 10.13.4 was made available to Mac users on 29 March 2018.

The update includes support for external graphics processors (eGPUs), but only the following AMD cards were supported at the time – Nvidia external graphics card support was not present.

• AMD Radeon RX 570
• AMD Radeon RX 580
• AMD Radeon Pro WX 7100
• AMD Radeon RX Vega 56
• AMD Radeon RX Vega 64
• AMD Vega Frontier Edition Air
• AMD Radeon Pro WX 9100

The following functions will be available for Macs with Thunderbolt 3 support:

• Accelerate applications that use Metal, OpenGL, and OpenCL.
• Connect additional external monitors and displays.
• Use virtual reality headsets plugged into the eGPU.
• Charge a MacBook Pro while using the eGPU.
• Use an eGPU with your MacBook Pro while its built-in display is closed.

Mac users are also now seeing warnings when they open 32-bit apps. The warning reads “[app name] is not optimized for your Mac. This app needs to be updated by its developer to improve compatibility”.

Apple has already warned developers that 32-bit apps’ days are numbered on the Mac. The company has already said that High Sierra will be the last macOS to run 32-bit apps without compromise, and that it plans to stop support for 32-bit apps on the Mac although it’s not clear when that deadline will be. More about what the App is not optimized for your Mac warning means here.

Other new features in macOS 10.13.4 include:

• A new Privacy message will appear when Apple is requesting personal information. It has an icon that looks like two people shaking hands. This messages will only appear in Apple apps
• ‘Ink Cloud’ wallpaper (this was previously only available on the iMac Pro).
• Support for Business Chat (in the US and Canada) – this means you can carry out an iMessage conversation with a business.
• Support for external graphics processors (see those listed above).
• A fix for a problem with graphics corruption on the iMac Pro.
• A new keyboard shortcut to jump to the last tab open in Safari (Command+9).
• Ability to sort Safari bookmarks by name or URL.
• A fix for a bug that stops links appearing in Messages.
• Usernames and password fields will only be completed in Safari when selected to improve data security. There will also be new warnings in Safari if you are interacting with forms that require credit card information on unencrypted web pages.
• Displays warnings in the Safari Smart Search Field when interacting with password or credit card forms on non-encrypted web pages.
• Displays privacy icons and links to explain how your data will be used and protected when Apple features ask to use your personal information.

Not present in the latest update, but thought to be coming soon:

• The iBooks Mac app is expected to soon be renamed Books (same will happen in iOS).
• Support for Messages on iCloud (so all your Messages can be stored in the cloud) – the option to enable or disable Messages in the Cloud is now available in Messages > Preferences > Accounts.

macOS 10.13.3 Supplemental Update

From time to time when Apple needs to get out an emergency fix in a hurry the company issues a Supplemental Update.

The macOS 10.13.3 Supplemental Update includes a fix for a bug that is causing characters from the Telugu alphabet (an Indian language) to crash iPhones, iPads and Macs.

You can read more about the text bomb that was crashing iPhones and Macs here.

macOS High Sierra 10.13.3

The 10.13.3 update to High Sierra addressed an issue where an incorrect password could be used to unlock App Store preferences.

That vulnerability allowed someone to gain access to App Store settings in System Preferences. If they did so they could enable App Store settings that would automatically install app updates which could put your Mac at risk (although the app update would have to go through the Mac App Store and be approved by Apple, and it would only work if the Mac was already logged in as an administrator.)

The 10.13.3 update also offered additional fixes for the Spectre and Meltdown vulnerabilities mentioned below.

Apple also confirmed that this version of macOS also includes a fix for the ChaiOS text crash bug. Find out more about the malicious link that is capable of crashing iOS and macOS if you click on it from the Messages app here. Apple also says that the update “addresses an issue that could cause Messages conversations to be temporarily listed out of order.”

macOS 10.13.2 Supplemental Update

To protect against ‘Spectre’ Apple issued a Supplemental Update to macOS 10.13.2 which includes a Spectre fix for Safari and WebKit.

Installing mac OS 10.13.2 Supplemental Update will update Safari to version 11.0.2 (13604.4.7.1.6) or version 11.0.2 (13604.4.7.10.6). If the update isn’t installed on your Mac automatically, visit the App Store and click on Updates.

In early January 2018 Apple confirmed that Macs, iPhones and iPads were affected by flaws in Intel chips known as Meltdown and Spectre.

Apple confirmed that Meltdown had already been addressed in macOS 10.13.2 and this is discussed in the next section. For more information about Meltdown and Spectre read: List of Mac viruses, malware and security flaws.

macOS High Sierra 10.13.2

This version of High Sierra arrived on 6 December 2017. Apple said that this update improved the stability, compatibility and security of your Mac, and is recommended for all users.

According to the company the update

• Improves compatibility with certain third-party USB audio devices
• Improves VoiceOver navigation when viewing PDF documents in Preview
• Improves compatibility of Braille displays with Mail

The update also addressed the Meltdown and Spector vulnerabilities (prior to them becoming widely known). In January 2018 Apple confirmed that macOS 10.13.2 also protects users from the Meltdown bug associated with flaws in Intel chips. The company issued a statment saying: “Apple released mitigations for Meltdown in iOS 11.2, macOS 10.13.2, and tvOS 11.2. watchOS did not require mitigation.” Read more about Meltdown and Spectre and other Mac security flaws and malware in our list here.

Following the revelations about Intel’s chips being affected by the Meltdown and Spectre flaws, Microsoft confirmed that its own update that protects PCs from the vulnerabilities could slow older PCs down. Luckily it doesn’t appear that macOS 10.13.2 has a detrimental effect on Macs. We ran Geekbench and Cinebench before and after installing the update on a 2013 iMac and saw slightly lower Geekbench – 11213 before, 11142 after, while Cinebench seemed to be better scoring 67.98fbs & 410cb CPU before, and 69.89 fps, 456 cb CPU after. We don’t think there is any reason to be concerned about these slight differences in test results.

High Sierra 10.13.2 came in conjunction with Security Update 2017-002 for Sierra and Security Update 2017-005 for El Capitan. This Security Update addresses 22 security issues across the three versions of the operating system.

According to Intego: “Apache, Directory Utility, Intel Graphics Driver and Kernel all received some attention. Mail received a fix for an issue that could cause S/MIME encrypted emails to be sent out unencrypted. Directory Utility and Screen Sharing Server had some work done to it to fix what was left of the root vulnerability. The Kernel received the most attention with 8 issues addressed that could lead to an application reading restricted memory contents and execute arbitrary code with kernel privileges.”

All in all November was rather a bad month for Apple security-wise, with the root access bug gaining a lot of media attention (more here, plus you can read about how to fix the MacOS Root Bug here). There have even been suggestions that High Sierra is Apple’s worst release yet in terms of bugs and missing functionality (on the basis that Apple has been forced to make quick updates due to issues with the software).

You can download macOS High Sierra 10.12.2 here, or visit the App Store on your Mac and choose Updates.

Security Update 2017-001

Apple issued Security Update 2017-001 for macOS High Sierra 10.13 and macOS High Sierra 10.13.1 on 29 November.

The security update addressed the root bug issue where an attacker could bypass administrator authentication without supplying the administrator’s password, according to Apple’s accompanying notes. 

The flaw in macOS High Sierra (discovered on Tuesday 28 November 2017) allowed root access to a Mac without the need for a password. A malicious user could access your Security & Privacy settings in System Preferences, enter root as User Name, and, without any need for a password, gain all the administrator rights. Allowing them to change the user password, change your settings for downloading applications, and more.

Apple notes that if you recently updated from macOS High Sierra 10.13 to 10.13.1, you should reboot your Mac to make sure the Security Update is applied properly.

Apple offers this guide for those who wish to confirm that their Mac has Security Update 2017-001:

1. Open the Terminal app, which is in the Utilities folder of your Applications folder.
2. Type what /usr/libexec/opendirectoryd and press Return.
3. If Security Update 2017-001 was installed successfully, you will see one of these project version numbers:

• opendirectoryd-483.1.5 on macOS High Sierra 10.13
• opendirectoryd-483.20.7 on macOS High Sierra 10.13.1

macOS High Sierra 10.13.1

The newest update to High Sierra (High Sierra 10.13.1) was issued on 31 October 2017 and brings performance improvements, security enhancements and bug fixes, along with new emoji.

That update became available to those on Apple’s developer beta program Monday 23 October and the Public Beta program a day later. 

• The update fixes a vulnerability in the WPA2 Wi-Fi standard that could allow attackers to exploit weaknesses in the WPA2 protocol to decrypt network traffic.
• It also includes new emoji including t-rex, vampire, brain, zebra, giraffe hedgehog, a gender neutral face and more. (The inclusion of Halloween related emoji was a good indication that the update would arrive by 31 October).

macOS High Sierra ‘Supplemental Update’

Apple issued a ‘Supplemental Update’ on 5 October. The update fixes the following:

• A vulnerability that could expose the passwords of encrypted Apple File System volumes.
• A vulnerability that could allow a hacker to steal usernames and passwords of accounts stored in Keychain using a third-party app.
• A cursor bug in Adobe InDesign.
• An issue where Yahoo messages couldn’t be deleted in Mail.

High Sierra bugs and vulnerabilities

There have been a number of vulnerabilities in High Sierra that Apple has needed to quickly fix. Below you will find details and advice for how to remedy them.

Password revealed in Terminal

One High Sierra bug discovered at the end of March 2018, can be exploited to reveal passwords.

Luckily, if you have the most recent version of High Sierra installed your Mac is unaffected.

However, if you are running macOS 10.13.1 to 10.13.3, your password can be revealed using a Terminal command, the details are outlined by mac4n6 here.

The person who discovered the vulnerability wrote: “It may not be noticeable at first (apart from the highlighting I’ve added of course), but the text frogger13 is the password I used on a newly created APFS formatted FileVault Encrypted USB drive with the volume name SEKRET.”

Luckily, the bug appears to have been fixed in a later update to High Sierra, so if you haven’t yet updated we suggest you do so.

macOS High Sierra root bug

Your Mac can be hacked into thanks to a MacOS High Sierra root access flaw that allows administrative access to your Mac without a password.

All a malicious user would need to do is enter root as a User Name, allowing them to change settings in System Preferences.

You would have to have already logged onto your Mac and left it unattended for the flaw to be implemented.

We have information on how to protect yourself from the issue here: How to fix macOS High Sierra root bug – stop strangers accessing your Mac.

Apple issued Security Update 2017-001 at the end of November, and then macOS 10.13.2 on 5 December, to address the security issue, so if you haven’t yet updated you should do so now via the  App Store on your Mac.

Security issues in High Sierra

A security researcher has already claimed that he has discovered a way to extract passwords from the keychain in High Sierra.

Synack head of research Patrick Wardle has demonstrated code that is said to extract passwords from the Keychain without requiring a master password.

However, while concerning, this security vulnerability isn’t limited to High Sierra. It is also present in older versions of the MacOS – and Apple has reassured users that: “MacOS is designed to be secure by default, and Gatekeeper warns users against installing unsigned apps, like the one shown in this proof of concept, and prevents them from launching the app without explicit approval. We encourage users to download software only from trusted sources like the Mac App Store, and to pay careful attention to security dialogs that macOS presents,” according to Gizmodo.

While it hasn’t confirmed this, it seems likely that the Supplemental Update issued by Apple on 5 October addresses this vulnerability.

High Sierra problems

With every new version of the Mac operating system there tend to be a few issues, despite the fact that Apple runs an intense beta testing program. Below you will see any details we have of problems with High Sierra, and where available the fix for them.

Issues updating macOS: macOS could not be installed on your computer

We were confronted with the above error message: “macOS could not be installed on your computer” when attempting to update from 10.13.2 to 10.13.3. As you can see from the below image, the warning stated that:

“The path /System/Installation?packages?OSinstall.mpkg appears to be missing or damaged. Quit the installer and restart your computer and try again”.

Unfortunately every time we tried again we saw the same message. In the end we were able to enter maCOS by exiting the installer. 

If you are experiencing this particular issue let us know in the comments below. There are some suggested fixes here.

Problems with Fusion Drives and APFS

If you have a Fusion Drive you might want to hold off updating to High Sierra, although it should work fine, it just won’t be able to take advantage of one of the new features in High Sierra, the new Apple File System (APFS). More on APFS below, 

APFS is limited to Macs with Flash storage (or SSDs). Excluding Fusion Drives, which combine Flash with a Hard Drive, and older Hard Drive equipped models.

Apple’s head of software engineering Craig Federighi has confirmed that APFS will be coming to those models soon, however.

In May 2018, Federighi responded to a Mac user who asked whether APFS was ever going to make it to the Fusion Drive, saying “We intend to address this question very soon..”

This wasn’t the first time Federighi had emailed a member of the public with the news, according to a MacRumors report back in September 2017, he wrote an email response to a user saying: “Yes, we plan to add support in a future update.”

The press release accompanying the High Sierra release also stated that Apple plans to introduce APFS support for Fusion Drives, and standard hard drives, in the future.

The support for APFS on Fusion Drives was pulled from the beta in back in June 2017, likely to be due to stability problems and bugs. It hasn’t made it back into the beta since.

Because APFS was included in the early beta, anyone who was running the beta on a Fusion Drive equipped Mac may encounter issues if they try to update to the final version of High Sierra.

This shouldn’t affect anyone who hasn’t been running the beta version of High Sierra, but if you have been running High Sierra beta on your Fusion Drive equipped iMac then beware that you will need to follow Apple’s advice to convert your Fusion Drive back to the previous HFS+ format before installing High Sierra. 

Apple’s instructions, which you can read here suggest that you should first make a Time Machine back up, then create a bootable installer of High Sierra, and reformat the drive before recovering your data from the Time Machine backup.

Apple also outlines how to overcome this particular challenge using Internet Recovery, but advises that it is only for advanced users.

Compatibility with Apps

There may also be issues with apps you use not working properly in macOS High Sierra. To find out if you are likely to encounter issues read: Which Apps won’t work in High Sierra?

New features in macOS High Sierra

Sierra brought some big new features to the Mac, such as Siri and Apple Pay – so what’s new in High Sierra?

MacOS High Sierra brings changes with it that you might be unaware of because they are all happening ‘under the hood’.

These changes to the core technologies include:

• A new Apple File System that will change the way the Mac stores your data, as well as make copying files faster.
• Improvements that will enhance 4K video playback (and reduce the space taken up by those videos).
• The graphics capabilities will be improved, bringing VR to supported Macs.

High Sierra reminds us of Mac OS X Mountain Lion and Mac OS X Snow Leopard – two updates that built on the OS changes introduced in the previous year’s versions (Lion and Leopard respectively), and focused more on the underlying technologies, with fewer changes to the outside. Keeping Sierra as part of the name certainly seems to back this up.

However, there are ways in which these core technologies will improve your Mac experience in a way you will notice. Speaking on 1 August, Tim Cook talked briefly about the “immersive gaming, 3D and virtual reality experiences made possible with the upcoming release of macOS High Sierra”.

There are also some new features coming to some of the apps Apple ships with macOS, such as the ability to turn off autoplaying video in Safari, and new advanced editing tools in Photos.

You can also expect to see updates to:

• Mail
• Siri
• iCloud
• Spotlight
• Notes
• Messages

We’ll discuss the changes coming to all of those apps below, addressing the ‘core technologies’ later on in this article.

Safari

Note Safari 11 is available for earlier versions of the macOS too.

New features in Safari 11 will help you personalise your experience when surfing the web. You can refine your settings for particular websites – making the text bigger for example on one site, or adjusting your location settings for another.

Apple is determined to make surfing the web a more pleasant experience, much to the dismay of advertisers, as a result, there will be no more auto-playing videos and no more cookies tracking your surfing habits and aiding advertisers who want to target ads to your interests.

Apple sells this as Intelligent Tracking Prevention which identifies trackers and keeps your browsing history between you and your internet provider rather than third parties.

What this means to users is that in macOS High Sierra, Safari automatically blocks audio and video on every site visited unless you specifically tell Safari that you want to hear the audio/video playback. Once you’ve ‘told’ Safari that a certain website can play audio and video, it should remember that the next time you visit the site (because who wants to enable it for every YouTube video they watch?).

As a final nail in the advertiser’s coffin, Apple will make all pages that support Safari Reader appear thus in your browser – with ads stripped out. For more information read How to use the new features in High Sierra. 

Photos

The Photos app for Mac is gaining some new organisation tools including an always-on side bar (like we had in iPhoto). This new side bar will make it easier to find things, or at least that’s Apple’s aim.

There will be a redesigned Edit view along with new editing tools including Curves for fine-tuning and Selective Color for making adjustments within a defined colour range. You’ll also find new professionally inspired filters.

Speaking of editing, Live Photos will gain a new Loop effect, so you can create a looping video, as well as a Bounce effect, which will play the action forward and backwards.

There’s also a Long Exposure effect coming which will use Live Photos to blur water or extend light trails for a slow-shutterspeed-like effect. You’ll also be able to capture Live Photos from within FaceTime.

Your People Album will get larger thumbnails and more accurate grouping of the ‘Faces’ (and this will stay in sync across all your devices if you use iCloud Photo Library.

Apple’s also introducing lots of new Memories categories – including pets, babies, outdoor activities, performances, weddings, birthdays and sporting events, and you’ll be able to easily filter photo collections by your favourite criteria.

Other handy changes in Photos include:

• Viewing past imports in chronological order
• The ability to do various functions right from the toolbar, such as rotate and favourite batches of images
• The selection counter will tell you how many things you have selected
• Filtering photo collections according to criteria
• Photos will support external editors, e.g. Photoshop can launch within Photos and save edits to the Photos library
• Third-party projects extensions that let you order framed prints, create web pages and more

Mail

Apple has also tinkered with the Mail app for MacOS High Sierra.

Updates will include improvements to search to make it easier to find what you are looking for amid our ever growing inboxes.

Top Hits adds a section at the top of your search results that includes the messages deemed to be most relevant to your search. These Top Hits are based on the mail you’ve read, the senders you reply to most often and people you have designated VIP status. According to Apple, the more you search, the smarter it gets.

Mail will also offer a long-requested feature; split-screen view when running the app full-screen.

Essentially, if you’ve got the Mail app open full-screen in macOS High Sierra and you want to send a new email, the composition window will open on the right-hand side of the screen instead of a new window, as currently it does in macOS Sierra.

Siri

Apple remains the only major AI player to offer the choice between a male and female voice, and these voices are going to get even more natural in macOS High Sierra.

Siri’s voice will be much more expressive and less robotic. You can expect more changes in expression and intonation.

Siri is more than just a pretty voice, though. It will be taking on the role of DJ, learning your preferences based on what you listen to (if you’re an Apple Music subscriber) and making recommendations, as well as helpfully putting together playlists for you.

Spotlight

The main addition to Spotlight appears to be integration with flight information. You’ll be able to enter your flight number to see arrival and departure times, terminals, gates, delays, and more.

Spotlight results will also include multiple Wikipedia pages when there is more than one answer to your query.

Notes

We think this one is a great addition – you’ll be able to Pin your most frequently used notes to the top so you can easily find them. This sure beats having to re-save a Note every time we access it so that it doesn’t get buried.

You’ll also be able to add tables to Notes.

Messages

This is perhaps one of the most exciting elements of the new Mac and iOS operating systems.

Your Messages are going to be stored in iCloud, so if you ever lose your phone you won’t lose all your messages, and more importantly, your Messages will be in sync across all your devices, so you won’t see alerts on your Mac for messages you have already read on your iPhone.

Because Messages will be stored in the cloud they won’t take up space on your Mac or iPhone either.

Apple File System

Now we’ve covered the fun stuff (i.e. the apps we use every day). Onto the under the hood changes that will hopefully enhance our overall experience on our Macs come this autumn.

First up is the introduction of the Apple File System (APFS) on the Mac. APFS arrived on our iPhones earlier this year in an update to iOS 10, and when it arrived the first thing we all noticed was that we got gigabytes of space back following the update. This is because Apple has rearchitected the way it stores data on its devices.

But APFS will do more than reduce the amount of space our data takes up. It will also make duplicating a file and find the size of a folder instantaneous.

It also keeps files safe with built-in encryption, helps protect data from power outages and system crashes, and offers simplified data backup, according to Apple.

And perhaps most importantly, it is compatible with HFS drives and data, so you shouldn’t lose any data (although we’d always recommend that you back up!), and is designed with future advancements in storage technology in mind.

Why is this so exciting for Mac users? In addition to offering increased security when compared to the standard HPF system and built-in drive encryption, it offers a dramatic speed bump in file transfer speeds – ideal for those that move/copy/duplicate large files.

The introduction of APFS may even free up a bit of storage like it did for iOS users when Apple introduced it in iOS 10.3!

Video

High Sierra will also see Apple move to the H.265 video standard to support better 4K playback. H.265, also known as HEVC (High Efficiency Video Coding) compresses video 40% more than H.264, and means high-def videos will take up less space on your Mac. High-quality video streaming will be possible too.

It’s not just about watching videos, though. The hardware accelerations on the new iMac and MacBook Pros will make HEVC encoding and editing possible.

(H.265 will also be arriving in iOS 11 for iPhone 7 and 7 Plus, and the next iPhone.)

Metal 2

The Metal technology built into macOS makes it possible for apps to use the full power of the graphics processors. The incoming Metal 2 update brings new capabilities in machine learning, virtual reality and external GPU support.

The API has also been refined, and Apple claims it offers improved performance.

In conjunction with Thunderbolt 3, Apple will offer external GPU support on supported Macs (although this is expected to be a later addition, coming in Spring 2018).

Apple is offering an External Graphics Developer Kit to developers of apps that use Metal, OpenCL, and OpenGL. It costs £749 and will furnish them with all the hardware and software they need to optimise their app, it includes:

• Sonnet external GPU chassis with Thunderbolt 3 and 350W power supply
• AMD Radeon RX 580 8GB graphics card
• Belkin USB-C to 4-port USB-A hub
• Promo code for $100 towards the purchase of HTC Vive VR headset

Find out more about this here.

Virtual Reality

Apple will be offering support for VR content creation for the first time in High Sierra and as a result, developers will be able to create immersive gaming, 3D and VR content on the Mac.

These capabilities are limited to the new 2017 iMac with Retina 5K display, the new iMac Pro coming in late 2017 and any supported Mac paired with an external GPU (although the latter will be delayed until Spring 2018).

Developers will be able to use peripherals like the HTC Vive VR headset and apps like Final Cut Pro X, SteamVR, Epic Unreal 4 Editor and Unity Editor to create immersive new worlds, says Apple.

Regarding its own video suite – Apple says that Final Cut Pro X will add support for professional 360-degree workflows with the ability to import, edit and export 360-degree video, “later this year”.

Already, Steam is optimising their SteamVR platform for macOS and enabling connection of the HTC Vive headset, according to Apple.

This is in part thanks to the new Metal 2 technology introduced as part of the update that’ll give the existing Mac range a hefty boost in terms of graphical power, and signifies a huge step in the VR world; only months ago, Oculus claimed its Mac support was on hold due to the power required to use the headset.

Will this change now? Only time will tell, but we imagine it will be the case. 

Read next: Can you use Oculus Rift with Mac?

Read about how macOS High Sierra compares to Windows 10.