If you need to run graphics intensive apps on your Mac you don’t have to wait while it struggles - even older Macs can get a boost if you add a eGPU. Here’s how it’s done.

• Which eGPUs work with Macs
• Which Macs can use an eGPU?
• How to use a eGPU with an older Mac
• How to use an eGPU with a Mac
• The performance boost you can expect to see
• Which Mac apps benefit most from an eGPU?

Apple is not know for making it easy to use add third party hardware to their computers. In fact it is notoriously difficult, often impossible, to update a Mac. However, this all changed when Apple introduced a way to use external graphics processor units or eGPUs in MacOS High Sierra, now Mac owners can improve the graphics capabilities of their Macs by adding an external graphics processor.

Even before the change in High Sierra a small, but active, community of users had been enjoying the relatively cheap way to boost graphic performance on the Mac, but the arrival of High Sierra made this even easier. And the process became easier still when Apple launched Mojave in 2018.

Which eGPUs work with Macs

Apple has collaborated with digital cinema production manufacturing company, Blackmagic Design to create their own eGPU units which are sold in the Apple Store. There are two to choose from:

• Blackmagic eGPU including the Radeon Pro 580 (£599/$699, buy it here)
• Blackmagic eGPU Pro including the Radeon RX Vega 56 (£1,999/$1,999, buy it here)

The Blackmagic eGPU is the unit we will discuss below, as we were provided with one from Blackmagic Design to try out.

However, there are other alternatives available, depending on your budget, needs and upgradability preference, such as the Sonnet eGFX Thunderbolt 3 system (£258, buy it here) but you would need to purchase a compatible graphics card separately.

Before you rush out to purchase your eGPU, note that at the moment Apple’s macOS only officially supports AMD based graphics processors. You can also get an Nvidia based eGPU to work on the Mac, but expect it to require some extra tinkering.

The second thing to consider is that Apple’s official support for eGPUs is only for newer Macs that have a Thunderbolt 3/USB-C interface. However, this doesn’t rule out older machines entirely, as you will find out if you read on.

Which Macs can use an eGPU?

Officially you need a Thunderbolt 3-equipped Mac, running macOS High Sierra 10.13.4 or later to use an eGPU, although we will demonstrate below that it is possible to use an eGPU with an older Mac.

If you are lucky enough to own one of the more recent Macs with a USB-C interface you are pretty much good to go. Most eGPUs use a USB-C connection and will be automatically detected by your Mac when you plug them in, and should work straight away, as long as you have macOS High Sierra 10.13.4 or later installed.

If you have an older Mac we address that below. Otherwise skip to the following section for how to use an eGPU with your Mac.

How to use a eGPU with an older Mac

As long as you have a Thunderbolt port on your Mac, you should be able to use an eGPU, following the advice below. However, Apple doesn’t officially support this.

We were able to use a BlackMagic eGPU with a late 2013 13in MacBook Pro. This MacBook features an integrated intel Iris graphic processor. It was slow back in 2013 and it’s very slow by today’s standards so it’s the perfect candidate for a graphics upgrade.

What you need

Before you start, make sure you buy the correct hardware and that you have a compatible Mac. We recommend you read this and this.

If like us, you want to use an eGPU with an older MacBook, with a Thunderbolt 2 or even version 1 interface, the first thing you will require is a USB-C to Thunderbolt adaptor.

There are some third party adapters, but we would recommend sticking to Apple’s own one which we know works - and should continue to work after any software updates (£49/$49, buy it here). You’ll also need a separate Thunderbolt 2 to 2 cable in addition, but it’s likely you already have one if you have previously plugged anything into your Thunderbolt port.

You also need to be running the latest macOS, which at the time of writing is MacOS Mojave 10.14.2. You can use High Sierra as well, but the latest OS offers a simpler way to choose which apps use the external eGPU hardware when it is connected. With Mojave running you also no longer require to have an external display connected, for it to work. Unless you want to of course. We didn’t use an external display in our test, as we’re more interested in video and photography editing app performance.

Here’s how to use a BlackMagic eGPU with an older Mac:

Before you begin we recommend that you back up your Mac. As you will see from the next step, if everything goes wrong you may need to reinstall MacOS, losing all your data in the process. So don’t move to the next step before backing up.

When we first set up our Mac to work with a eGPU it was necessary to download a patch and install it on the system. Installing the patch requires Admin privileges but is fairly straightforward and doesn’t require too much tech knowledge. That said, we did find it necessary to disable system integrity protection and run a script to alter macOS. Just be aware that there is a possibility that you could damage your Mac, requiring you to re-install MacOS from scratch loosing all your files in the process - so make sure you back-up any important data you have on the device before proceeding as we said above.

However, you no longer need to go to these lengths. Rather than installing a patch, running a script, and altering the OS, you can now just download an automate-eGPU EFI zip file, copy it to a USB thumb drive and boot from it.

1. Before you start make sure the eGPU is disconnected.
2. Get the automate-eGPU EFI v1.0.5 package here.
3. Copy the EFI folder onto a FAT32 formatted USB stick. You will need to format the USB stick first. Use MS-DOS FAT, Master Boot Record. We have a tutorial on formatting drives here.
4. Boot from the external USB drive (hold down the Option/Alt key when you start up your Mac and select EFI Boot).
5. Once you are logged in, plug in the eGPU.
6. Now execute the following commands in Terminal:
   sudo pmset -a gpuswitch 2
   sudo pmset -a gpuswitch 0
7. Shift+Cmd+Q and press enter to log out
8. Log in again

We recommend you check out this site for more advice as the method may change over time and with subsequent updates to macOS.

How to use an eGPU with a Mac

Once you’ve gone though the steps to enable eGPU support if required, you can plug the eGPU unit into one of your Thunderbolt 1, 2 or 3 ports.

1. Plug in the eGPU. Apple recommends using a Thunderbolt port on the left hand side of the MacBook Pro for best results.
2. Once plugged in the eGPU should be automatically recognised by Mojave and an icon will appear in the menu bar like the one in the screen grab below. If you can see the icon it mean that the eGPU has been recognised and is ready to go. (This is also the icon you will need to click on to safely disconnect your eGPU unit once you are ready to unplug it.)

   

3. There is just one more step before you can use the eGPU with your applications. The simplest method requires that you are running the latest version of MacOS Mojave. If you are running Mojave go to your Applications folder.
4. Find the application you want to use with the eGPU unit with, right-click on it, and choose Get Info from the menu.
5. Half way down the app info window, in the General tab, you should see a tick box with a Prefer External GPU option. Tick it.

Now, whenever you open that app, it should use the eGPU unit instead of the integrated GPU inside your Mac.

The performance boost you can expect to see

We were using an old 13in MacBook Pro (late 2013 model) which uses a Thunderbolt 2 interface. If, like us, you are using an older Macs you are likely to benefit considerably from this upgrade as the old internal GPUs were very slow. You will see an even better improvement if you’re have a Thunderbolt 3 (USB-C) Mac.

We tested our old 2013 MBP 13” as well as a 2018 13in MacBook Pro with a simple Final Cut Pro X render test, as follows:

Final Cut Pro Test: 6 minute 1080p video render to H264

• 2018 13in MacBook Pro, 2.7GHz Core i7 16GB, Intel Iris Plus Graphics 655 = 2:47.33
• 2018 13in MacBook Pro, 2.7GHz Core i7 16GB, WITH BM eGPU = 1:03.82
• 2013 13in MacBook Pro, 2.4GHz Core i5, 8GB, Intel Iris 5100 Graphics = 5:39.74
• 2013 13in MacBook Pro, 2.4GHz Core i5, 8GB, WITH BM eGPU = 1:48.26

As you see, our results are very positive, the eGPU made a big improvement compared to the integrated graphics processor. Not only did it speed up rendering times considerably, it also allowed us to edit 4K video in real time with multiple effects applied to the timeline, without skipping frames. And that’s in high-quality playback mode as well.

Which Mac apps benefit most from an eGPU?

Unfortunately, not all app will benefit from the graphics process upgrade as some task solely rely on the CPU processor to run exporting task.

We saw great results in Final Cut Pro X, as well as DaVinci Resolve. Premiere CC did not have eGPU support when we first ran these tests. The good news is that the latest CC update does seem to work. We’ve not had a chance to re-run the tests however.

Adobe Photoshop and Lightroom Classic did take advantage of the eGPU performance, but only when we were editing, compositing and colour correcting images. It however did not use the eGPU when we were exporting and compressing our images. We recommend that you check whether the app you want to use will benefit from eGPU acceleration.