Thunderbolt External Gpu For Mac

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'Using an External GPU via Thunderbolt on a MacBook Pro

The Thunderbolt™ 3 eGFX box is a low cost expansion chassis designed to house an external graphics card. Connected to the computer via Thunderbolt 3, the additional GPU power instantly upgrades a regular laptop or a mini PC and makes it possible to do things that would normally require a high-end workstation or gaming computer. If you've got a Mac with Thunderbolt 3 that is running High Sierra or the latest Mojave version of the macOS, then you can now connect your Mac to an eGPU - or 'external GPU' - that allows you to.

My plan was to attempt to run an external Graphics Card (GPU) via the Thunderbolt port of my MacBook Pro 13' (Retina, Late 2012) and see see if I could improve on the poor performance of the built-in Intel 4000 GPU (included in my Macbook Pro's 2.5GHz i5 processor).

The theory is as follows, GPU's are typically connected via PCIe ports and since there are several manufacturers that provide Thunderbolt to PCIe expansion chassis for MacOS, physically connecting a GPU to a Thunderbolt equipped Macintosh is easy. However, there is a catch; as delivered MacOS doesn't support or recognize a GPU connected to an external PCIe chassis via Thunderbolt.

Conducting some pre-purchase research on the internet was not encouraging since most of the opinions confirmed that MacOS will not drive displays over Thunderbolt and even if it would, since the PCIe bus is so much faster than Thunderbolt, a GPU will be continuously constrained by the bandwidth of the Thunderbolt interface. There were also a few articles by people that had successfully enabled video cards over Thunderbolt.

Due to the increasing popularity of Thunderbolt accessories, the price of PCIe Thunderbolt docks has dropped to the point where I was prepared to take the plunge and buy an AKiTiO 'Thunder2 PCIe Box' to connect to my MacBook Pro (Retina, 13, Late 2012). This particular AKiTiO box supports a single half length PCIe card and supplies 25W of bus power (as per the PCIe specification).

Since my Macbook is fitted with a Thunderbolt 1 interface and the AKiTiO chassis has a Thunderbolt 2 interface (2x the transfer rate of Thunderbolt 1), my chosen combination will have the Thunderbolt 1 port on the MacBook Pro as the speed limiting bottleneck, however I still wanted to see what performance could be possible.

Half length GPU's are much rarer than full length ones which tends to limit the available choice, notwithstanding since MacOS 10.10 natively supports NVIDIA cards, I acquired a cheap Gigabyte GT 740 GPU (with 2 gig of ram), and a 600w AT (ATX?) Power supply to power the GPU (actually the GPU would have also been fine with a much less powerful power supply).
(See 'Troubleshooting' notes below for general info on external power supply, jumpering and cables.)

I then followed the excellent instructions found on www.journaldulapin.com/2013/08/24/a-thunderbolt-gpu-on-a-mac-how-to. In addition to the guide, I used 'Nano' contained within the MacOS terminal to actually perform the editing of the files and I also needed to issue the command 'sudo kextcache -system-caches' to actually get the MacOS to boot and recognise the revised kext files. (and check permissions after editing.) With these tasks complete, I rebooted my MacBook with the GPU connected via Thunderbolt, startup was normal on the MacBook and the external screen remained blank. Once the log-on screen was completed, the external screen came to life and I was running two screens. NB I have successfully run this modification on pretty much all versions of MacOS 10.10 (up to 10.10.5 at the time of writing).

'About this Mac' reported the two screens and also identified the Intel GPU for the MacBook Screen and the NVIDIA Card for the external display.

Interestingly the 'System Information' correctly identifies the GPU and screens under 'Graphics and Displays', but is unable to identify the NVIDIA card under PCI. (Because it's used via Thunderbolt?)

How does it perform, in short - very well.

Macbook Pro External Graphics Card

I ran two benchmark tests, firstly the FurMark test from Geeks3D GPU Test, this reported 8fps for the Intel HD4000 GPU and 19fps on the NVIDIA GT 740.

I also ran Cinebench R15, this test generated much more interesting results, since under Cinebench the same GPU operated both screens, that is if I set the MacBook to run its built-in screen as the main display then Cinebench rendered using the Intel HD 4000 GPU on both displays, however if I started the application with the external screen connected to the Thunderbolt port as the main screen, then Cinebench would use the NVIDIA GT 740 to render on both screens. (? I'd think the internal display only uses the internal graphics, as that's the only connection it has. The 740's output is only connected to the external display. Unless it's using the 740 for rendering and passing that data to the Intel 4000's shared vram onboard memory? Like a 2013 Mac Pro uses the 2nd GPU for rendering/computations.)

This was a surprise, as all of my prior research had suggested that MacOS was incapable of using an external Thunderbolt GPU to render on the built-in MacBook Screen (only an Apple supplied discrete GPU such as the one fitted to the MacBook Pro 15' was capable of displaying on internal screen)

Thunderbolt External Gpu For Mac

For Cinebench the following was observed:

  • Intel HD 4000 GPU: MacBook Screen 15.25fps : External Screen 14.47fps
  • NVIDIA GT 740 (T'Bolt): MacBook Screen 40.32fps : External Screen 43.73fps.

Following loading of the NVIDIA 'Web Driver' (and re-modifying the kext files since they were reset), I ran Cinebench again and now 48.32fps was returned on the external screen and 41.34fps on the MacBook screen. so the NVIDIA driver is worth about 10% more speed on an external display for this test, however it had no real effect on the internal display. Clearly there is some additional overhead needed to pass a signal back along the Thunderbolt connection to the built-un display after it has been rendered by the external GPU.
(FYI: Nvidia web drivers are specific to OS X version/build numbers (and build numbers change when applying OS X security updates, which means another Nvidia driver update is required). I try to keep links to the latest (non-beta) drivers and CUDA posted at Nvidia's website for OS X 10.9.5 and later on the Video topics page. As noted above however, they will need to be modified for cards used in a Thunderbolt case. (Updates appear first in Nvidia Web Driver Prefs before they post a D/L page.)
BTW: Resetting the Mac's nvram will clear Nvidia Web driver setting and revert to the standard OS X driver, which doesn't support some PC Nvidia card models. (For instance as of this post date (fall 2015), the Nvidia GTX 780Ti and Titan Black require the Nvidia Web drivers *and* OS X 10.9.2 or later. The Nvidia GTX 750Ti, GTX950/960/970/980/980 Ti and Titan X require OS X Yosemite or later *and* the Nvidia web drivers.) I don't use OS X 10.11 El Capitan but I suspect these driver edits/mods will not work with 'System Integrity Protection' enabled.
)

Based on the benchmark tests, the NVIDIA GT 740 over Thunderbolt 1 offers over double (and almost triple) the performance of the Intel HD 4000 GPU, and you also get CUDA enabled with the GT 740.

Regardless of the selected GPU or screen, Cinebench returned the same CPU performance index. (GPU not used for that test.)

While I don't generally play games, I own a copy of Deus Ex - Macintosh Edition (not steam) and I also purchased a copy of Bioshock Infinity to see how the system would perform in this environment. In both cases I had the GPU connected to a HD TV and set the game to 1920 x 1080 resolution and standard quality settings. Deus Ex comfortably ran at a average of 55 - 60 fps and Bioshock made 25 - 30 fps. Increasing Bioshock to high quality settings has the frame count remain at about 25 - 30 fps. Both game exhibited some vertical sync issues (resulting in some screen tearing when panning the view)

A faster GPU would no doubt work better, and with modifications to the AKiTiO enclosure, a full length GPU card could be accommodated.

The GT 740 does not appear to be limited by the Thunderbolt 1 interface speed, however this is not a particularly fast GPU and maybe a faster card would show limitations to the Thunderbolt 1 standard. Recent Macintoshes have the faster Thunderbolt 2 ports and will be less affected.

Notwithstanding this simple and relatively cheap peripheral has effectively extended the life of my MacBook Pro and also made it more flexible. If Apple improves the Mac mini specification (bring back the Quad Core i7 option please) I think that the combination of its Thunderbolt 2 ports and the external GPU will make quite powerful and cheap alternative to a desktop Macintosh (which was my original motivation for this experiment).

A final word of warning, MacOS needs to be hacked for the card to be recognised and while Thunderbolt is a hot-pluggable standard, unplugging the Thunderbolt box with a GPU while the mac is running causes a Kernel Panic that requires a restart to clear.
-Andrew'

The idea of an external graphics card (eGPU) was once the talk of fantasy, but that’s no longer the case. Thanks to Thunderbolt 3 and its high-bandwidth 40Gbps transfer rate, external enclosures can now accommodate high-end graphics cards.

That means you can now supercharge the visual performance of your Mac computer, even if it’s a laptop. There are some caveats to doing this, namely a limited number of supported graphics cards and the high price of getting started.

That said, let’s take a look at what you need to add an external GPU to your Mac or MacBook and which ones you should buy.

What You’ll Need

First, you’ll need a Thunderbolt 3-capable Mac or MacBook model. Thunderbolt 3 uses the USB-C connector, and appears on the following models:

  • MacBook Pro, late 2016 and newer
  • MacBook Air, 2018 and newer
  • iMac, 2017 and newer
  • iMac Pro, 2017
  • Mac Pro, 2019

In addition to owning one of these Apple computers, you’ll also need macOS High Sierra 10.13.4 or later. Finally, you’ll need to purchase two additional items, either separately or as part of a bundle:

  1. A Thunderbolt 3 eGPU enclosure, into which your graphics card will slot.
  2. A macOS-compatible graphics card.

With all this in place, you should be able to put the graphics card into the enclosure, then plug the enclosure into your Mac for a significant boost in graphical fidelity. However, you may still be limited in how you can use your eGPU.

The Limitations of External GPUs on macOS

Not every application you run can take advantage of your eGPU. In many cases, you’ll need to plug an external monitor directly into the eGPU enclosure to see the benefit. This is the case with many 3D games and VR applications.

Some pro-level software designed to take advantage of multiple GPUs will just work as you’d expect. This includes 3D modeling apps and video editors, but it’s worth confirming your application will see a benefit before you buy an eGPU.

Some applications and games have received patches allowing you to accelerate the built-in display on your iMac or MacBook. However, this is something that developers must enable on their end, so it’s worth keeping in mind if you’re thinking of using an eGPU purely to accelerate your in-built display.

Thunderbolt External Gpu For Mac Os

External Graphics Card for Mac

At present, there are only a small number of compatible graphics cards you can use as an eGPU on your Mac. They are all AMD cards.

According to Apple, these are:

  • AMD Polaris cards: Radeon RX 470, RX 480, RX 570, RX 580, and Radeon Pro WX 7100
  • AMD Vega 64 cards: Radeon RX Vega 64, Vega Frontier Edition Air, and Radeon Pro WX 9100
  • AMD Radeon RX Vega 56

The Best eGPU Enclosures and All-in-One Options for Mac

1. Blackmagic eGPU

A great first place to look when searching for an external GPU for your Mac is with the Blackmagic eGPU. This eGPU sports a Radeon Pro 580 graphics processor with 8GB of GDDR5 memory. It also offers several additional ports to use.

Thanks to up to an 85W power delivery feature, you can use one of the two included Thunderbolt 3 ports to power your MacBook Pro without needing to worry about an additional power brick. There is also an HDMI 2.0 port and four USB 3.0 ports.

Blackmagic includes a 0.5m Thunderbolt 3 cable so you can get started with the eGPU right out of the box.

2. Sonnet eGFX Breakaway Box 650

Sonnet eGFX Breakaway Box 650Sonnet eGFX Breakaway Box 650 Buy Now On Amazon

You’ll need to provide your own Mac-compatible graphics card when using the Sonnet eGFX Breakaway Box 650. The 650W power supply supports 375W cards that require up to an additional 100W of peak power.

There is also 100W of power delivery reserved to power a laptop with the one Thunderbolt 3 port. A 0.7m 40Gb Thunderbolt 3 cable is included with the enclosure.

3. Razer Core X Chroma

External Gpu Imac

Razer Core X ChromaRazer Core X Chroma Buy Now On Amazon $399.99

If you already have a graphics card in mind, the Razer Core X Chroma is another great enclosure choice. The 700W power supply can support a graphics card up to 500W. There is also 100W available for powering a laptop via the Thunderbolt 3 port. On the rear of the enclosure, you’ll find four USB. 3.1 ports and a Gigabit Ethernet plug.

When it’s time to install the card, there is a quick-release handle on the enclosure to bring out the slider tray. No tools are needed for a quick and easy installation. The enclosure sports additional cooling and open vents in the body for the best thermal performance.

4. Sonnet eGFX Breakaway Puck

The Sonnet eGFX Breakaway Puck Radeon is made for portability. The all-in-one option sports a built-in Radeon RX 560 GPU. Along with three DisplayPort ports, there is an HDMI 2.0 port and a single Thunderbolt 3 plug.

The Thunderbolt 3 port can provide up to 60W of power to your MacBook Pro. Sonnet includes a 0.5m Thunderbolt 3 cable. While the additional VESA mounting bracket allows you to place the eGPU on the back of a monitor to free up desk space.

5. PowerColor Mini Pro

PowerColor Mini ProPowerColor Mini Pro Buy Now On Amazon $477.41

Thunderbolt External Gpu For Macbook Air

The PowerColor Mini Pro sports a built-in AMD RX570 graphics card with 8GB of memory, so you’ll be comfortably set up to attach it to your Mac. Thanks to an external power adapter, the eGPU is lightweight and compact, making it perfect for a desk. It also cuts down on heat inside the enclosure.

External gpu for macbook pro thunderbolt 2

On the front of the eGPU is the Thunderbolt 3 port and two USB 3.0 ports to connect another device like an external hard drive. The rear of the box sports several display connection options—two DisplayPort plugs, two HDMI ports, and a single DVI-D port. There is also a Gigabit Ethernet plug on the side of the box for a fast Internet connection.

Turn Up the Graphics With the Best Mac External GPU

Even though a MacBook or MacBook Pro is a powerhouse by itself, adding an external GPU can bring the visual performance of your Mac to new heights. Fortunately, there are other ways to bring more of a desktop-like experience to your laptop, too.

Mac Compatible External Gpu

For instance, take a look at these great Thunderbolt 3 docks for Your MacBook Pro.

External Nvidia Gpu For Mac

Read the full article: The Best External GPU for a MacBook Pro

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