DisplayLink limits on a Mac
Updated
Short answer
DisplayLink lets a Mac drive more external displays than its chip supports, by compressing the picture in software and sending it over USB to a chip in the dock. The trade-offs: a compressed picture, extra CPU work, no brightness or input control from the Mac, a Screen Recording permission, and some protected video won't play.
When you need it
Some Apple silicon Macs drive only one external display on their own. A DisplayLink dock is the usual way to add a second. Guidance from Apple's published specs:
| Mac | External displays on its own |
|---|---|
| MacBook Air (M1) | 1 |
| MacBook Air (M2) | 1 |
| MacBook Air (M3) | 2 (two only with the lid closed; one with it open) |
| MacBook Air (M4) | 2 |
| MacBook Air (M5) | 2 |
| MacBook Pro 13″ (M1 or M2) | 1 |
| MacBook Pro 14″/16″ (M1 Pro) | 2 |
| MacBook Pro 14″/16″ (M1 Max) | 4 |
| MacBook Pro 14″/16″ (M2 Pro) | 2 |
| MacBook Pro 14″/16″ (M2 Max) | 4 |
| MacBook Pro 14″ (M3) | 2 (two only with the lid closed; one with it open) |
| MacBook Pro 14″/16″ (M3 Pro) | 2 |
| MacBook Pro 14″/16″ (M3 Max) | 4 |
| MacBook Pro 14″ (M4) | 2 |
| MacBook Pro 14″/16″ (M4 Pro) | 2 |
| MacBook Pro 14″/16″ (M4 Max) | 4 |
| MacBook Pro 14″ (M5) | 2 |
| MacBook Pro 14″/16″ (M5 Pro) | 3 |
| MacBook Pro 14″/16″ (M5 Max) | 4 |
| Mac mini (M1) | 2 (one on Thunderbolt and one on HDMI) |
| Mac mini (M2) | 2 |
| Mac mini (M2 Pro) | 3 |
| Mac mini (M4) | 3 |
| Mac mini (M4 Pro) | 3 |
| iMac (M1 or M3) | 1 |
| iMac (M4) | 2 |
| Mac Studio (M1 Max or M1 Ultra) | 5 |
| Mac Studio (M2 Max or M2 Ultra) | 5 (M2 Ultra: up to 8) |
| Mac Studio (M4 Max or M3 Ultra) | 5 (M3 Ultra: up to 8) |
What to expect
- Picture. Video is compressed before it goes over USB. Still work looks fine; fast motion and fine gradients can show artefacts.
- Refresh rate and resolution depend on the DisplayLink chip in the dock, not on your Mac. Check the dock's spec sheet for your monitor's mode.
- CPU. Compression runs on the Mac, so busy screens cost some CPU and battery.
- No DDC. Apps can't change the monitor's brightness, volume or input over DisplayLink. Software dimming still works.
- Permission. The DisplayLink Manager app needs Screen Recording permission to capture the picture.
- Protected video (some streaming services and players) may not play on DisplayLink screens.
Is my dock DisplayLink?
If it needed the DisplayLink Manager app to show a picture, yes. Thunderbolt docks and plain USB-C hubs carry the Mac's own video and need no driver; they're limited by the Mac's display count instead.