Article

About Multi-GPU and Multi-Display Setups

Learn about the different ways that a user can connect external GPUs and external displays to a Mac computer.

Overview

A user can have multiple GPUs and displays built in or connected to a Mac computer, with each display driven by a specific GPU. You should be aware of these possible configurations and how they might affect your app’s graphics rendering or compute processing workflows. Test as many configurations as possible, and be prepared to inform your users about recommended setups for optimal app performance.

An image showing a single MacBook Pro, multiple external GPUs, and multiple external displays.

In general, external GPUs can provide more processing power than many built-in GPUs. However, the external Thunderbolt 3 bus that connects an external GPU to a Mac typically has a lower bandwidth than the built-in bus of a built-in GPU. Thus, data transfers between a Mac and an external GPU can be more expensive than data transfers between built-in GPUs within a Mac.

Built-in GPU with a Built-in Display

Some Macs have only one built-in GPU (integrated or discrete). This GPU always drives the built-in display.

A system diagram showing a single built-in GPU within a MacBook Pro.

Multiple Built-in GPUs with a Built-in Display

Some Macs have multiple built-in GPUs (integrated, discrete, or both). Any of the built-in GPUs can drive the built-in display.

A system diagram showing two built-in GPUs within a MacBook Pro.

One or More External Displays

Single or multiple external displays can be connected to a Mac. All built-in or connected displays are driven by only one built-in GPU at any given time (different built-in GPUs can't drive different displays). On Macs that have both an integrated and a discrete GPU, the discrete GPU always drives any external displays connected to the system.

A system diagram showing two external displays connected to a MacBook Pro.

One or More External GPUs

Single or multiple external GPUs can be connected to a Mac. However, an external GPU cannot drive the built-in display (only a built-in GPU can do so). If an external GPU needs to send data to the built-in display, that data must first be transferred from the external GPU to the built-in GPU that drives the built-in display.

A system diagram showing two external GPUs connected to a MacBook Pro.

External GPU with an External Display

An external GPU can be connected to both a Mac and an external display. In this setup, the external GPU always drives the external display (a built-in GPU can never do so). If a built-in GPU needs to send data to the external display, that data must first be transferred from the built-in GPU to the external GPU.

A system diagram showing an external GPU connected to both a MacBook Pro and an external display.

Multiple External GPUs and Multiple External Displays

A user can connect multiple external GPUs and external displays to the system. Additionally, some external GPUs can be connected to multiple external displays.

A system diagram showing an iMac Pro connected to an external display, an external GPU, and another external GPU that's also connected to two additional external displays.

See Also

Selecting GPUs on Mac

Device Selection and Fallback for Graphics Rendering

Demonstrates how to work with multiple GPUs and efficiently render to a display.

Device Selection and Fallback for Compute Processing

Demonstrates how to work with multiple GPUs and efficiently execute a compute-intensive simulation.

About External GPUs

Learn how to support external GPUs in your macOS apps and games.

About GPU Bandwidth

Learn about some of the main factors that affect bandwidth between a GPU and a system on a Mac.

Handling External GPU Additions and Removals

Register and respond to external GPU notifications initiated by a user.

Getting Different Types of GPUs

Obtain, identify, and choose suitable GPUs for your app.

Getting the GPU that Drives a View's Display

Keep up to date with the optimal device for your display.