Now that MacOS 10.13.4 is available supporting external graphics cards on compatible Mac devices, is the additional cost of an enclosure and add-in card worth the investment? That could be a yes for graphics-heavy applications, but there are limitations; the feature only supports AMD’s graphics cards and the Mac device must have an integrated Thunderbolt 3 port. There is also no external GPU support in Boot Camp and currently no “official” external GPU support for the Mac’s built-in screen.
Recent benchmarks using a 2015 15-inch MacBook Pro with a Core i7-6820HQ processor and a discrete AMD Radeon Pro 460 graphics chip showed a significant performance increase when using the Radeon RX 580 add-in graphics card in an external enclosure. For instance, in the OpenGL test in Cinebench R15, the Pro 460 chip managed 56 frames per second while the external RX 580 clocked in at 86 frames per second.
On the gaming front, World of Warcraft using Apple’s Metal graphics API, a 1080p resolution, and high detail settings saw an average of 71 frames per second on the internal graphics chip, and 141 frames per second on the external graphics chip. Meanwhile, in Civilization VI, the internal GPU scored an average of 66 frames per second while the external GPU hit an average of 73 frames per second using the OpenGL graphics API, a 1080p resolution, and High detail settings.
Here are a few other benchmarks:
GFXBench 4 Metal: Offscreen (1080p)
- T-Rex: 354 (internal) – 835 (external)
- Manhattan: 159 (internal) – 425 (external)
- Manhattan 3.1: 130 (internal) – 349 (external)
GFXBench 4 GL: Offscreen
- T-Rex: 249 (internal) – 435 (external)
- Manhattan: 101 (internal) – 173 (external)
Other notable mentions about the recent MacBook Pro benchmarking is that Hitman‘s built-in testing tool worked just fine when benchmarking the laptop’s internal graphics chip but caused a hard crash of the system when attempting to test the external GPU. After that, the game wouldn’t load at all, requiring additional troubleshooting. Meanwhile, Final Cut Pro doesn’t support external graphics, an Apple-developed application that could certainly benefit from the higher-powered solution.
“eGPU support in macOS High Sierra 10.13.4 is designed to accelerate Metal, OpenGL, and OpenCL applications that benefit from a powerful eGPU,” Apple clearly states. “However, not all applications support eGPU acceleration. Check with the application’s developer to learn more.”
Apple’s external graphics card support includes the following:
- Radeon RX 470 and RX 480 (Sapphire Pulse Series recommended)
- Radeon RX 570 and RX 580 (Sapphire Pulse Series recommended)
- Radeon Pro WX 7100
- Radeon RX Vega 56 and RX Vega 64 (Sapphire and XFX recommended)
- Radeon Pro WX 9100
Support for external graphics cards stuffed into enclosures is nothing new for Windows 10 gaming laptops from the likes of Asus and Alienware, but the feature is somewhat of a late arrival on MacOS laptops. Right now, Apple’s external GPU support is fresh out of the oven and obviously needs more time to fully cook and become less of the “hit-and-miss” feature now served up in MacOS 10.13.4.
As previously stated, the external GPU only supports external displays; it won’t power the Mac’s built-in display. This limitation is supposedly software-only that will likely be addressed on an application-by-application basis by third-party developers in the near future.