Connection guides

Daisy-chaining monitors on a Mac: what works when MST does not

macOS has no MST, so DisplayPort and USB-C monitor chains mirror on a Mac. See when a Thunderbolt chain extends, the chip limits and what to use instead.

NYBreaking Tech editorial · Accountable publisher: Feroz Sheikh
Editorial update: 2 November 2026 · 5 min read

THE SHORT ANSWER

macOS does not support DisplayPort MST for independent extended displays, so a chain built from a monitor’s DisplayPort-out port, over DisplayPort or a USB-C DP Alt Mode link, shows the same picture on both screens. Dell’s daisy-chain guide lists those chains as duplicate mode only on macOS. A Mac can extend across a daisy chain only over Thunderbolt: the first monitor must connect by Thunderbolt and have a Thunderbolt downstream port. Even then, Apple says a hub or daisy chain does not raise the Mac’s display limit. For most chips one Thunderbolt port carries up to two displays; Apple lists three for M5 Pro and four for M5 Max MacBook Pro.

Manufacturer documentation · Not physically tested by NYBreaking

Why a DisplayPort or USB-C chain mirrors on a Mac

MST is the catch. A monitor with a DisplayPort-out port chains the next screen using Multi-Stream Transport (MST). Plugable states that Windows and ChromeOS support MST, while macOS does not support MST for multiple independent extended displays.
Dell lists the result. In Dell’s daisy-chain guide, the macOS column shows DisplayPort and USB-C DP Alt Mode chains as “Duplicate mode only”. Dell also says macOS only allows monitor daisy chaining through Thunderbolt.
Dell’s Mac article says the same: Macs using USB-C (DP Alt Mode) do not support monitor daisy-chaining, and in that setup both monitors are in clone mode.

So a popular USB-C hub monitor such as the Dell U2723QE, which chains over USB-C plus DisplayPort-out, mirrors on a MacBook. Our U2723QE daisy chain on a MacBook Air page covers that case. If your screens already match, see why a MacBook mirrors monitors through a dock.

Which chain types extend on a Mac

Chain type	Result on macOS	What to check
Monitor 1 on DisplayPort, DP-out to monitor 2 (MST)	Same image on both	Dell: duplicate mode only on macOS
Monitor 1 on USB-C DP Alt Mode, DP-out to monitor 2 (MST), for example a U2723QE	Same image on both	Dell: Macs using DP Alt Mode do not support daisy-chaining
Monitor 1 on Thunderbolt with a Thunderbolt downstream port	Extended, up to the Mac’s limit	The Mac port must be Thunderbolt; use the active Thunderbolt cable Dell specifies
HDMI between monitors	Not a daisy chain	Dell: HDMI does not support daisy chaining

Apple’s 2026 Studio Display is one Thunderbolt option: Apple lists a Thunderbolt 5 upstream port with 96W charging and a downstream Thunderbolt 5 port for accessories or daisy-chaining additional displays, and says the number of chained displays depends on the Mac’s chip and Thunderbolt bandwidth. Apple’s specs for the 2022 Studio Display list one Thunderbolt 3 upstream port and three USB-C ports at up to 10Gb/s, which are not described as display outputs. Dell’s Mac article names Thunderbolt monitors such as the UP2720Q as a valid first monitor and lists Thunderbolt 4 models including the U2724DE and U2725QE; check the user guide of your exact model for a downstream Thunderbolt port that carries video.

Your Mac’s limit still applies

Apple says a supported hub or daisy chain can put several displays on one Thunderbolt port, but does not increase the maximum number of displays the Mac supports. Apple also says to connect the display with the highest resolution first.

MacBook Air M4 and M5: up to two external displays, two at up to 6K 60Hz or 4K 144Hz. Closing the lid does not add a third. Up to two displays can share one Thunderbolt port. See MacBook Air M4 with two monitors through one dock.
MacBook Air M3: Apple lists one external display with the lid open and a second only with the lid closed. Details: M3 MacBook Air dual monitors.
MacBook Air M1: Apple lists one external display, so a chain cannot add a second native screen. The workaround is DisplayLink: two monitors on a base M1/M2 MacBook Air.
MacBook Pro: Apple lists up to two displays over a single Thunderbolt port for M3, M4, M4 Pro, M4 Max and M5 models, three for M5 Pro and four for M5 Max. The total for each chip is in MacBook Pro M4/M5 multiple monitors by chip.

How to set up a Thunderbolt chain

Confirm the Mac port is Thunderbolt or USB4, not plain USB-C: how to check your port.
Confirm the first monitor has a Thunderbolt upstream port and a downstream Thunderbolt port that carries video. A monitor with only DisplayPort-out will chain using MST and mirror.
Use the Thunderbolt cable that came with the monitor. Dell says a Thunderbolt chain needs an active Thunderbolt cable, and notes that the USB-C cable supplied with a Mac may only charge.
Give each monitor its own power. Dell lists this as a daisy-chain requirement.
Connect the highest-resolution display directly to the Mac first, as Apple advises, then the second display to the first.
In System Settings > Displays, choose extended rather than mirrored for each screen.

Bandwidth still limits the chain. Intel says Thunderbolt 4 drives up to two 4K 60Hz displays or one 8K 60Hz display on one connection, and Dell notes that chained monitors may run at lower resolution depending on the bandwidth each one needs.

What to use instead of a monitor chain

Thunderbolt dock with two video outputs. CalDigit says Macs with M1 to M5 Pro chips can use up to two displays through the TS4 over one cable. See the CalDigit TS4 port roles and how to pick a dual-monitor dock.
Two direct cables. Each Thunderbolt port (or HDMI port where fitted) can drive one screen, within the same Apple limits.
DisplayLink for screens beyond the chip limit. DisplayLink screens are driven by software over USB and need the DisplayLink Manager app. See DisplayLink vs Thunderbolt and three monitors on an M4 Pro MacBook Pro with one cable.

Sources you can inspect

Based on official documentation reviewed 2026-11-02. Steps are general; follow the manual for your exact model. No physical test by NYBreaking.

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