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Plugable UD-3900C4 Review 2026 - Quad HDMI USB-C Dock Specs

7.4 Very Good
Adrian Cel By Adrian Cel

The Plugable UD-3900C4 is a USB-C docking station built for one specific desk problem: four 1080p monitors from a single laptop cable. Plugable gets there with a hybrid video layout. HDMI 1 and HDMI 2 use DisplayLink USB graphics, while HDMI 3 and HDMI 4 use DisplayPort Alt Mode with MST from the host laptop. On Windows 10 or later and ChromeOS 100 or later, that means four extended 1920x1080 displays at 60Hz if the host USB-C, USB4, or Thunderbolt port supports DisplayPort Alt Mode with MST. On macOS, the story changes. Plugable says MacBooks can use up to three unique extended displays because macOS does not support MST, and the fourth display mirrors instead of extending. The rest of the dock is more useful than the display headline suggests: 96W certified USB-C laptop charging, one downstream USB-C 5Gbps port with 20W charging, four USB-A 5Gbps ports, Gigabit Ethernet, separate headphone and microphone jacks, and an SD 4.0 UHS-II card reader. Plugable lists it at $344.99 with a current direct price around $244.99, and the Amazon listing uses ASIN B09TSQYGKS. If you run a Windows or ChromeOS workstation with four modest monitors, the UD-3900C4 is unusually direct. If you run a Mac or want 1440p or 4K screens, it is the wrong target.

Best for four 1080p monitors

Pros & Cons

What We Like

  • Four HDMI outputs support four 1080p displays from one USB-C cable on compatible Windows and ChromeOS hosts
  • Hybrid DisplayLink plus MST design avoids relying on DisplayLink for every monitor
  • 96W certified host charging is enough for many 13-inch to 16-inch laptops
  • UHS-II SD reader, Gigabit Ethernet, audio input and output, and five downstream USB ports cover most office desks
  • Two-year Plugable warranty and lifetime support are better than many generic quad-display docks

What Could Be Better

  • All HDMI outputs are limited to 1920x1080 at 60Hz

    Workaround: Use a different dock, such as a triple 4K DisplayLink or Thunderbolt model, if your monitors are 1440p or 4K.

  • macOS cannot run four unique extended displays because it lacks MST support

    Workaround: Mac users should treat this as a three-display dock at most, or choose a DisplayLink dock designed around Mac multi-monitor setups.

  • HDMI 3 and HDMI 4 require a host USB-C port with DisplayPort Alt Mode MST

    Workaround: Check the laptop's USB-C, USB4, or Thunderbolt specs before buying. A data-only USB-C port will not run the full display setup.

  • DisplayLink setup adds driver and permission friction, especially on macOS

    Workaround: Install DisplayLink Manager before connecting monitors on macOS, then grant Screen Recording permission in System Settings.

  • Not a good fit for gaming, protected streaming video, or color-critical creative work

    Workaround: Use native GPU outputs or a Thunderbolt dock for high-motion, DRM-protected, or color-sensitive work.

Display Support

Max Displays: 4
4 displays (Quad 1080p@60Hz on Windows 10 or later and ChromeOS 100 or later. HDMI 1 and HDMI 2 use DisplayLink, while HDMI 3 and HDMI 4 use DisplayPort Alt Mode MST from the host.)
1920x1080 @ 60Hz
3 displays (Maximum unique extended display setup on macOS. Plugable says the fourth display mirrors because macOS does not support MST.)
1920x1080 @ 60Hz
2 displays (Two DisplayLink HDMI outputs can work when the driver is installed, even if the host's MST support is unavailable.)
1920x1080 @ 60Hz
1 display (Any HDMI output is limited to 1080p at 60Hz. This dock is not meant for 1440p or 4K monitor setups.)
1920x1080 @ 60Hz

Ports & Connectivity

USB Ports

1x USB-C 3.2 20W
4x USB-A 3.0

Video Outputs

2x HDMI 1.3
2x HDMI 2.0

Network

1x Ethernet (1 Gbps)

Audio

1x 3.5mm headphone
1x 3.5mm microphone

Card Readers

1x SD (SD 4.0 / UHS-II)

Full Specifications

General
Manufacturer Plugable
Model UD-3900C4
Release Date 2022-06
MSRP $344.99
Connectivity
Host Connection USB-C
Max Data Rate 10 Gbps
Driver Required DisplayLink
Display Output
Max Displays 4
4x Display 1920x1080 @ 60Hz (Quad 1080p@60Hz on Windows 10 or later and ChromeOS 100 or later. HDMI 1 and HDMI 2 use DisplayLink, while HDMI 3 and HDMI 4 use DisplayPort Alt Mode MST from the host.)
3x Display 1920x1080 @ 60Hz (Maximum unique extended display setup on macOS. Plugable says the fourth display mirrors because macOS does not support MST.)
2x Display 1920x1080 @ 60Hz (Two DisplayLink HDMI outputs can work when the driver is installed, even if the host's MST support is unavailable.)
1x Display 1920x1080 @ 60Hz (Any HDMI output is limited to 1080p at 60Hz. This dock is not meant for 1440p or 4K monitor setups.)
Ports (9+ total)
USB-C 3.2 1x (20W)
USB-A 3.0 4x
HDMI 1.3 2x
HDMI 2.0 2x
Ethernet (RJ45) 1x 1 Gbps
Audio (3.5mm-headphone) 1x
Audio (3.5mm-microphone) 1x
SD Card Reader 1x
Power
Power Input DC-barrel
Laptop Charging Up to 96W

Compatibility

Windows (10+)

Full quad-display support when the host USB-C, USB4, or Thunderbolt port supports DisplayPort Alt Mode with MST. DisplayLink drivers usually install automatically through Windows Update.

macOS (10+)

Requires DisplayLink Manager and Screen Recording permission. Plugable supports up to three unique extended displays because macOS does not support MST. The fourth display mirrors.

ChromeOS (100+)

ChromeOS 100 or later has native DisplayLink support. Quad-display mode still needs Alt Mode MST support from the host USB-C path.

Known Issues

macOS four-monitor setups

Fourth display mirrors instead of extending

USB-C ports without DisplayPort Alt Mode MST

HDMI 3 and HDMI 4 cannot provide the full quad-display setup

Users needing 1440p, ultrawide, or 4K monitors

Resolution limit is 1920x1080 at 60Hz

7.4 /10

Our Verdict

Very Good

The Plugable UD-3900C4 is best for people who care more about screen count than resolution. Four 1080p monitors can be perfect for trading desks, support queues, dispatch dashboards, development logs, chat, documentation, and browser-heavy work. The dock does not try to be a Thunderbolt replacement. It uses a practical split: DisplayLink handles the first two HDMI ports, and the host GPU handles the second pair through MST. That makes the Windows and ChromeOS setup more flexible than a pure DisplayLink dock, but it also creates the dock's biggest gotcha. Your laptop must support DisplayPort Alt Mode with MST for the third and fourth HDMI ports, and macOS cannot use MST for four independent extended displays. The 96W charging is strong enough for most 13-inch to 16-inch laptops, the UHS-II SD reader is better than the basic card slots found on many cheaper docks, and the 20W front USB-C port is handy for a phone or small accessory. The trade-offs are clear. Every monitor tops out at 1920x1080 at 60Hz. DisplayLink still needs software on macOS and can cause the usual Screen Recording permission confusion. Gaming, protected streaming video, and color-sensitive creative work should stay off this dock. For a Windows hot desk with four 1080p HDMI monitors, though, the UD-3900C4 fills a niche that most USB-C docks ignore.

Available at Amazon

Frequently Asked Questions

Does the Plugable UD-3900C4 support four monitors?
Yes, on compatible Windows 10 or later and ChromeOS 100 or later systems. The UD-3900C4 supports four 1920x1080 displays at 60Hz using two DisplayLink HDMI ports and two DisplayPort Alt Mode MST HDMI ports. The host USB-C, USB4, or Thunderbolt port must support DisplayPort Alt Mode with MST for the full four-monitor setup.
Does the UD-3900C4 work with MacBooks?
Yes, but it is not a four-monitor Mac dock. Plugable says macOS can use up to three unique extended displays with the UD-3900C4 because macOS does not support MST. A fourth display will mirror instead of extending. You also need DisplayLink Manager and Screen Recording permission for the DisplayLink outputs.
What resolution do the HDMI ports support?
All four HDMI outputs support up to 1920x1080 at 60Hz. HDMI 1 and HDMI 2 are DisplayLink outputs, while HDMI 3 and HDMI 4 are DisplayPort Alt Mode MST outputs. The dock does not support 1440p or 4K display output.
Can the Plugable UD-3900C4 charge my laptop?
Yes. Plugable lists 100W Power Delivery with 96W certified charging to the host laptop. That is enough for many 13-inch to 16-inch laptops, including many MacBook Pro and Windows Ultrabook models.
Does the UD-3900C4 require drivers?
Yes for the DisplayLink outputs. Windows usually installs the DisplayLink driver through Windows Update, while macOS requires the DisplayLink Manager app. ChromeOS 100 or later has native DisplayLink support. HDMI 3 and HDMI 4 also require host DisplayPort Alt Mode MST support.
Is the Plugable UD-3900C4 good for 4K monitors?
No. The UD-3900C4 is a quad 1080p dock. If you need 4K displays, look at Plugable's triple 4K DisplayLink docks or a native Thunderbolt or USB4 dock instead.

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