Apple's Metal demo at WWDC 2018.

Apple will enable up to 4 external graphics cards in macOS 10.14 Mojave

Apple said Monday that it will enable external graphics processing unit (GPU) support via its Metal applications programming interface (API) across the Mac platform.

The Metal API enables developers to access the hardware for performance-hungry apps such as games and visual programs, and now Metal can enable games and other apps to take full advantage of the GPUs available via external graphics cards. It can now tap as many as four now.

Craig Federighi, senior vice president of software engineering, made the announcement at Apple’s keynote talk during its Worldwide Developer conference (WWDC) in San Jose, California. He said you can add up to four external GPUs on an iMac Pro and speed performance up to 6.5 times for some applications. He showed Fortnite running on a Mac.

Apple's laptops can benefit from up to 4 external graphics cards now.
Apple’s laptops and desktops can benefit from up to 4 external graphics cards now.

He showed a Unity demo from the Game Developers Conference running on a MacBook. It showed a beautiful forest with extreme amounts of detail and dynamic lighting. Metal will also enable better machine learning, accelerating machine learning applications from various third parties like IBM Watson.

Metal will also have a new tool, dubbed Create ML, that can be used to train machine learning applications such as vision recognition.

Dean Takahashi

Dean Takahashi is editorial director for GamesBeat at VentureBeat. He has been a tech journalist since 1988, and he has covered games as a beat since 1996. He was lead writer for GamesBeat at VentureBeat from 2008 to April 2025. Prior to that, he wrote for the San Jose Mercury News, the Red Herring, the Wall Street Journal, the Los Angeles Times, and the Dallas Times-Herald. He is the author of two books, "Opening the Xbox" and "The Xbox 360 Uncloaked." He organizes the annual GamesBeat Next, GamesBeat Summit and GamesBeat Insider Series: Hollywood and Games conferences and is a frequent speaker at gaming and tech events. He lives in the San Francisco Bay Area.