Welcome to our guide to Mac eGPUs, in which we explain the advantages of using an eGPU and round up the best buying options currently available.
It's certainly true that the iPhone and iPad are well suited to AR, as the popularity of mobile games in recent years means that these devices have plenty of graphical horsepower for titles, such as Pokemon Go, that work by superimposing computer graphics and data over images of the real world.
But that's not the case with all Apple products and - as any Mac gamer will tell you - graphics performance has always been something of an Achilles' heel for the Mac.
You need a lot of graphics power to run the latest 3D games and VR/AR software, but Apple has never shown much interest in gaming on the Mac. Many very expensive Mac models still rely on 'integrated' graphics - a small graphics chip built into the Mac's main processor (CPU) - rather than having a 'dedicated' graphics card (or GPU - 'graphics processing unit') that works alongside the main CPU and gives graphics performance a much bigger boost. And, of course, none of the current Mac range has any internal expansion slots that would allow you to install a new GPU in order to upgrade your graphics performance.
Budget and upgrade problems
Needless to say, VR and AR games and software need seriously good graphics performance too. And, in fact, the VR developers at Oculus once mocked Apple, saying that they would bring their Rift headset to the Mac "when Apple releases a good computer".
Recently, of course, Apple has launched the new iMac Pro, and has very much aimed this new model at VR developers. However, the least expensive version of the iMac Pro costs almost £5,000, so it'll be far too expensive for anyone but professionals and developers with a big IT budget.
There is hope for the rest of us, though. When Apple unveiled the iMac Pro last year, it also mentioned that it was planning to support 'external graphics cards' - or 'eGPUs' - with the new macOS High Sierra, some time in 2018. And it now looks as though that eGPU support will arrive in just a few weeks' time, with the macOS 10.13.4 update, which Apple says is due in spring 2018.
What's an eGPU?
As the name suggests, an eGPU is a graphics card that gives your Mac a real performance boost, but instead of being inserted into an internal expansion slot inside the Mac itself, the card is installed into an external box - often referred to as an 'enclosure' - that sits outside the Mac.
Inside the enclosure there's a 'PCIe' expansion slot, and a separate power supply for the graphics card, so you simply insert your new graphics card into the expansion slot and then connect the enclosure to your Mac via one of its Thunderbolt 3 ports. (Lots of Windows PCs have Thunderbolt 3 these days too and, in fact, many of the eGPUs on sale at the moment are designed by PC manufacturers for their own gaming PCs and laptops.)
What are the advantages of an eGPU?
One great advantage of using an eGPU is that you can have a slimline laptop that you use when you're out and about, then plug it into an eGPU when you get back home or back to the office - instantly turning your lightweight laptop into a heavyweight desktop computer capable of running high-end graphics software or the latest 3D games.
External graphics cards aren't new; they've been around for the best part of a decade. But it's only relatively recently that the high-speed Thunderbolt interface has provided the speed and performance that are really needed to cope with high-end 3D graphics, games and VR software.
The other problem on the Mac side of the fence was that the macOS itself simply wasn't designed to work with eGPUs (although there are a number of eGPUs already on sale that do seem to work quite well with Macs). That's why Apple's announcement last year was so important, as it meant High Sierra would allow you to simply plug in an eGPU and give your Mac an instant upgrade.
How do eGPUs work, and what do you need?
Officially, the eGPU support in High Sierra 10.13.4 is still in its beta testing phase, so the precise details of how it will work still have to be ironed out. However, Apple has already released some information to developers, so we have a few ideas on how this new technology will work when it arrives on the Mac this spring.
According to Apple, you'll need a Mac running High Sierra, and equipped with a Thunderbolt 3 interface in order to use it with an eGPU. Some manufacturers of eGPU products have hinted that they may also work with older Macs that have Thunderbolt 2, but the latest beta version of 10.13.4 seems to restrict High Sierra so that an eGPU will only work with Thunderbolt 3. And, during this beta phase, you need to connect the eGPU to a separate, external monitor too - although, hopefully, that won't be the case once the eGPU support is complete.
Which eGPUs are compatible with Macs?
At the moment, the only eGPU that is officially supported by Apple for running on High Sierra is the Sonnet eGFX Breakaway Box - which quickly sold out last year when Apple started offering it to developers who wanted to get started with new VR titles for the Mac. However, there are many other companies that make a wide variety of eGPU enclosures - including big-name PC manufacturers, such as HP, Dell and Asus.
Many of these eGPUs are specifically designed for use with Windows PCs, but most of them use a standard Thunderbolt 3 interface to connect to a PC, so it should also be possible to use them with a Mac that has Thunderbolt 3 as well (in fact, the brave hackers at the eGPU.io website have already figured out how to do this - and this is also a great site if you want to read more about eGPU technology in general). Some other manufacturers have already tested their eGPU products with the beta software on Macs - such as Akitio, with its Node eGPU - and promise good results. But, again, it is possible that Apple might limit High Sierra so that it only works with specific eGPU products that have been officially tested and approved by Apple.
It would be great, though, if Mac users were able to choose from the wide range of eGPUs that are already available for Windows PCs. These include big, bulky models, such as the HP Omen, which are almost as big as a desktop computer themselves, down to Sonnet's recently released Puck, which shrinks the eGPU enclosure down into something that is just about small enough to fit into a backpack.
The one big drawback of using an eGPU is that the enclosure itself generally costs £300-£500, and is normally sold empty - or 'unpopulated' - which means that you still have to pay for your new graphics card on top of that. Even so, an eGPU is still a lot less expensive than buying a completely new Mac, and once you've bought the eGPU enclosure you can continue to upgrade your Mac by buying newer, more powerful graphics cards as they are released in the future.
Sonnet eGFX Breakaway Box
Sonnet's eGFX Breakaway Box is the only eGPU enclosure currently approved by Apple for use with High Sierra - but even then, that's only if you buy it through Apple's own Developer Program. However, quite a few people have had good results when buying the Breakaway Box directly from Sonnet.
The company also has a long history of producing upgrade products for Macs, so this will very much be the 'safe' option for Mac users until Apple finally announces the full details of its support for eGPU technology with macOS 10.13.4 this spring.
Prices for the Breakaway Box start at around £320/$250 for a model with 350W power supply, but there are other models with an upgraded power supply (£348/$400) for really high-end graphics cards. The Developer Edition provided through Apple's Developer Program includes a Radeon RX580 graphics card (Amazon US sells this bundle for $699), but the standard versions of the Breakaway Box sold by Sonnet are empty ('unpopulated'), so you'll need to provide your own card.
The Breakaway Box includes a single PCIe expansion slot and the enclosure is large enough to house most full-size graphics cards. It connects to your Mac via a Thunderbolt 3 interface, and if you're using a laptop the Thunderbolt interface can even charge the laptop at the same time.
Interestingly, Sonnet says that it has tested the Breakaway Box with Thunderbolt 2 as well - which would be a great upgrade option for many older Macs. Unfortunately, we suspect that Apple will restrict High Sierra so that the eGPU support specifically requires Thunderbolt 3, so that's something we'll come back to once we have more info from Apple.
We're also dying to get our hands on Sonnet's new Breakaway Puck - a semi-portable eGPU enclosure that includes its own GPU and is small enough to fit into a backpack.
Razer Core V2
The Core V2 is primarily designed for use with Razer's own range of Windows-based gaming laptops, but this new model uses a standard Thunderbolt 3 port and seems to be Mac-compatible at the moment, so hopefully Apple will give the Core V2 its official seal of approval once it finally releases macOS 10.13.4 this spring.
And if you're a frustrated Mac gamer (is there any other type?) then the Core V2 might just be your idea of gaming heaven.
It's expensive, at close to £500 even before you budget for your GPU, but Razer brings all its gaming expertise and experience with high-end graphics cards to the Core V2. The machine-tooled metal case looks a lot more attractive than most of its rivals, with a smart metal grille on the front, and perforated side panel for cooling - which also smoulders with subdued lighting while you're getting into some gaming action. The Core V2 can even sync with the fancy lighting effects that you get from some of Razer's gaming mice and keyboards, many of which are Mac-compatible too.
Eye-candy aside, the Core V2 has a 500W power supply and is large enough to house most full-length graphics cards. And it's not just for gaming, either, as Razer says that it has tested the Core V2 with professional-level graphics cards such as the nVidia Quadro, which can handle high-end graphics and VR applications.
Throw in four USB 3 ports, and an Ethernet port that allow the enclosure to act as a hub for your MacBook laptop, and the Core V2 will appeal to both gamers and professional users alike.
Akitio makes a number of external enclosures that use Thunderbolt 3 to connect to a Mac or PC, but many of these are designed for devices such as external sound cards or high-performance storage systems, and they don't have the power or cooling systems required for high-end graphics cards, so be careful to make sure that the model you're looking at does actually work with graphics cards.
The main option for eGPU use at the moment is the Akitio Node, which costs about £320/$300; but, like most enclosures, it doesn't include a graphics card so you'll still have to budget for the GPU on top. The design of the Node is fairly straightforward - it's just a big black metal box with a single internal PCIe expansion slot and power supply, and a Thunderbolt 3 port on the back for connecting to a Mac or PC.
There's also a model called the Node Pro (whose price hasn't yet been announced), which has a second Thunderbolt 3 port and a DisplayPort connector for an additional monitor, which could be very useful if you want to use it in an office as a hub for a laptop with limited connectivity. But watch out for the more compact Node Lite, as that's not designed for use with an eGPU.
The Node enclosures are primarily designed for use with Windows PCs and, of course, Apple's support for eGPUs is still in beta. However, Akitio claims to have tested the Node with a Mac setup that "appears to work well", and the Node and Node Pro have already proven to be popular with many Mac users in the US.
Mantiz Venus (MZ-02)
It's not widely available in Europe or the UK at the moment, but the Mantiz Venus has proved popular with early-adopter Mac users in the US so hopefully it'll reach these shores soon.
The Venus enclosure is a bit on the bulky side, standing 215mm high, 163mm wide and 330mm deep. And, at $399 (about £281) on Amazon US, it's also a little more expensive than many of its rivals... and don't forget that you need to buy your own GPU as well. However, it does pack in lots of extra features that will help it to earn its keep, especially if you want to use it with a laptop that has limited connectivity.
As well as the standard PCIe expansion slot, the Venus includes a 550W power supply, which should be powerful enough for most high-end graphics cards, as well as being able to charge up a laptop at the same time. The bulky enclosure even provides room for a SATA connector for a hard drive or SSD that you can use to add some extra storage to your Mac.
The Venus uses Thunderbolt 3 to connect to a Mac or PC, but also includes no less than five USB 3 ports - two on the front and three round the back - along with an Ethernet port, which will be handy for laptop users who need Ethernet for their office network.
Somewhat oddly, the 'How To' guide for setting up the Venus with a Mac seems to have vanished from the company's website recently. But we're hoping that's because they're getting a new one ready for the launch of High Sierra 10.13.14 with its official support for eGPUs.