2-Port Multi Monitor Adapter - USB-C to 2x DisplayPort 1.2 Video Splitter - USB Type-C to DP MST Hub - Dual 4K 30Hz or 1080p 60Hz - Thunderbolt 3 Compatible - Windows Only

Dual Monitor Adapter | Windows® | Thunderbolt™ 3 Compatible

Product ID: MSTCDP122DP

2.5 stars (2 reviews) |
  • MULTIPLE MONITORS FOR WINDOWS: USB-C to DisplayPort splitter to drive 2x 4K 30Hz or 2x 1080p 60Hz DP displays using a USB-C DP Alt-Mode port (DP 1.2/HBR2/MST) w/ no video compression; Thunderbolt 3 compatible | Not compatible with macOS
  • CONVENIENCE: With a built-in 1ft cable, this bus-powered 2-port MST hub provides an easy method to connect up to two independent screens with any DisplayPort over USB Type-C Windows host device
  • COMPATIBLE WITH: Dell XPS / Precision / Latitude, Lenovo ThinkPad X1 Carbon / Extreme, Surface Laptop 3 / Book 3 / Pro 7, HP ProBook / EliteBook / Spectre / ZBook & smaller (Mini -ITX) computers | Requires host system supporting DP Alt Mode 1.2/HBR2/MST
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This USB-C to DisplayPort MST Hub lets you connect two DisplayPort monitors to your USB Type-C Windows device, conveniently helping you to maximize your productivity. 

Multitasking Made Easy 

With devices becoming more portable than ever, you can be limited to fewer video outputs and confined to your small integrated screen. This multi-stream transport hub solves that problem by enabling you to connect two separate displays to your USB-C computer, making multitasking much easier.  

Using this USB-C to dual DisplayPort monitor adapter, you can mirror your display onto additional monitors or stream independent content to each display, which makes it the ideal accessory for travel or hot-desking.  

Increase productivity with multiple screens

Astonishing Picture Quality 

MST technology uses your existing video card to minimize the use of system resources, while delivering UHD 4K resolutions for two monitors or displays simultaneously. With support for HD 1080p and UHD 4K, the dual-monitor splitter is perfect for all high-resolution applications such as graphic design and CAD drawing. 

productivity software displayed on two monitors

Hassle-Free Setup 

Multi-stream transport offers an easy setup, by natively working on any Windows device that supports DP Alt Mode over USB Type-C. This USB-C dual-monitor adapter is Thunderbolt 3 compatible, and offers plug-and-play installation with no drivers or software required. Additionally, this DP MST hub is powered by the USB-C port, meaning no external power cords are necessary.  

The MST Hub pictured with video adapters attached

MSTCDP122DP is backed by a StarTech.com 3-year warranty, and free lifetime technical support. 


  • Extend your desktop onto additional monitors or displays
  • Create dynamic digital signage with a panoramic video wall
  • Avoid side-scrolling by spanning across dual monitors
  • Edit media across additional displays in any orientation
  • Ideal for travel or hot-desking

Partner Numbers

  • Ingram Chile 3372931
  • UPC 065030864497


  • Windows 8 logo
  • Windows 7 logo
  • Windows 10 logo
  • Windows 11 logo
Microsoft Windows® 11, 10, 8/8.1, 7


Warranty Information Warranty 3 Years
Connector(s) 1 - Connector A USB-C (24 pin) DisplayPort Alt Mode
2 - Connector B DisplayPort (20 pin)
Environmental Operating Temperature 5°C to 35°C (41°F to 95°F)
Storage Temperature -20°C to 60°C (-4°F to 140°F)
Humidity 50-90%
Hardware AV Input USB-C
Ports 2
AV Output DisplayPort - 1.2
Audio Yes
Chipset ID MegaChips - STDP4320
Packaging Information Package Height 1.3 in [3.2 cm]
Package Length 6.8 in [17.2 cm]
Shipping (Package) Weight 4.7 oz [133.0 g]
Package Width 5.6 in [14.3 cm]
Performance Audio Specifications DisplayPort - 5.1 Channel Audio
Maximum Cable Distance To Display 6.6 ft [2 m]
Maximum Digital Resolutions 3840x2160 @ 30hz
Supported Resolutions

Note: MST shares 21.6 Gbps across all attached displays. Higher resolutions can restrict the available bandwidth with the remaining ports, please see our guideline below for determining an ideal resolution for your setup.

Average resolution bandwidth allocation

1920x1080 (High-definition 1080p) @60hz - 22%
1920x1200 @60hz - 30%
2560x1440 @60hz - 35%
2560x1600 @60hz - 38%
3840 x 2160 (Ultra HD 4K) @30hz - 38%

Note: Exceeding 100% will reduce functionality.

Wide Screen Supported Yes
Physical Characteristics Color Black
Cable Length 12.8 in [32.4 cm]
Product Length 15.2 in [38.6 cm]
Product Width 2.3 in [5.8 cm]
Product Height 0.6 in [1.4 cm]
Weight of Product 1.6 oz [44.0 g]
Power Power Source USB-Powered
Software OS Compatibility Microsoft Windows® 11, 10, 8/8.1, 7
Special Notes / Requirements Note DisplayPort 1.2 with MST+HBR2 support from the GPU is required for independent display output
Your USB-C equipped device must support video (DP alt mode) to work with this adapter
What's in the Box 1 - Included in Package MST hub
quick-start guide



15ft (5m) DisplayPort 1.2 Cable - 4K x 2K Ultra HD VESA Certified DisplayPort Cable - DP to DP Cable for Monitor - DP Video/Display Cord - Latching DP Connectors

Create high-resolution 4k x 2k connections with HBR2 support between your DisplayPort-equipped devices over longer distances

Your price


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Frequently Asked Questions


To set up a MST hub with your MST compatible system, complete the following:

  1. Plug the MST hub into a compatible DisplayPort 1.2 output from your computer.
  2. Plug the power into the MST hub.
  3. Plug your DisplayPort monitors or DisplayPort adapters/converters into the MST hub.
  4. Turn on your computer.

You should be able to detect the monitors in the display properties of your operating system.

If you are not getting any additional displays, try the following:

  • Verify that the latest display drivers are installed.
  • Press and hold the Scan button for five seconds on the MST hub.

When the monitors are detected in the display properties of your operating system, make sure that the resolutions that you are setting do not exceed the total data throughput of the DisplayPort host connection. You can verify the total data throughput (bandwidth) under the Product Overview tab for you device.


  1. Open the Intel, AMD, or Nvidia application that controls the display settings.  This is recommended over Windows Display Settings when using an MST product. Go to Settings and select the monitor that is not outputting a video signal.  Check that the resolution and refresh rate is correct for that model of display.  
  2. The product may be connected to a video source that does not support MST.  Note: macOS will not allow the displays to our product to be extended.
  3. In Windows, open Screen Resolution or Display Settings and ensure all numbered displays are set to Extend.  If some displays do not appear, press the scan button (where applicable) firmly for about half a second.
  4. The display configuration may be using too much bandwidth. An example would be two 4K displays and one 2560x1440 display. That configuration will exceed the bandwidth limitations of DP 1.2.  Also, be aware of displays with higher refresh rates.  A 120 Hz display will use twice the bandwidth of a 60 Hz version using the same screen resolution.
  5. One or more of the displays(s) connected to our MST hub may be set to the wrong video input. Use the display’s on-screen display menu to select the correct input.
  1. Try using shorter or higher quality video cables.
  2. Press the scan button (where applicable) on our product firmly for about half a second. Then open Screen Resolution or Display Settings and ensure all numbered displays are set to Extend.  For good measure, ensure each display is set to a 60 Hz refresh rate before trying to use a higher refresh rate.
  3. If using passive DisplayPort to DVI or HDMI cables or adapters, replace them with active DisplayPort to DVI or HDMI adapters (Ex. DP2DVIS, DP2HD4KS).
  • Note: these adapters will require a DVI or HDMI cable to be used to connect the monitors.
  1. The primary display adapter for the computer has an outdated or basic driver installed. Update the video driver using the manufacturer’s support site.

When you troubleshoot issues with an MST hub, there are some quick tests that you can complete to rule out potential problems. You can test to make sure that the following components are working correctly and are not the source of the issue:

  • Video cables

  • Video source

  • Video destination

  • MST Hub

To test your setup components, try the following:

  • Use the video cables, video source, video destination, and MST hub in another setup to see if the problem is with the components or the setup.

  • Use a different video cable, video source, video destination, and MST hub in your setup to see if the problem persists. Ideally, you should test a component that you know works in another setup.

Note: Some 4K displays, even if set to 1920x1080 resolution, will still reserve the full 4K bandwidth.  As a result, this may prevent some displays from outputting a video signal or prevent certain resolutions from being available on the other displays.

When you test your cables, it is recommended that you do the following:

  • Test each cable individually.

  • Use short cables when you are testing.

  • Eliminate the use of adapters, extenders, or splitters where possible.

When you test the MST hub with your computer system, do the following:

  • Make sure that the computer/graphics adapter is MST compatible. For more information, refer to the following FAQ: http://www.startech.com/faq/mst-hubs-gpu-compatibility.

  • Make sure that the latest graphics drivers are installed. The latest drivers are available on the website of the manufacturer of the graphics adapter.

  • Use compatible adapters. For example, DisplayPort to HDMI and not HDMI to DisplayPort.

Note: Drivers are not required for the MST hub.

To check to see if Windows is detecting the monitor, on a computer that is running a version of Windows 8 or Windows 10, do the following:

  1. On your keyboard, press the Windows key + X and click Control Panel.
  2. Click Appearance and Personalization, then click Display.
  3. In the left column, click Resolution or Adjust Resolution. Your monitors will be displayed as numbered icons.
  4. To see which monitors are detected, click the Display menu.
  5. To display the numbers on each of the connected monitors and see how the operating system has assigned their positions, click Identify.

To check to see if Windows is detecting the monitor, on a computer that is running a version of Windows 7, do the following:

  1. Right-click on the desktop and click Screen Resolution.
  2. To see which monitors are detected, click the Display menu.
  3. In the left column, click Resolution or Adjust Resolution. Your monitors will be displayed as numbered icons.
  4. To display the numbers on each of the connected monitors and see how the operating system has assigned their positions, click Identify.

If you are experiencing flickering issues with the MST hub, your monitors may be at a 59 Hz refresh rate. If they are at 59 Hz, you need to adjust the refresh rate to 60 Hz. In order to change your monitor's refresh rate, complete the following:

  1. Right-click anywhere on your desktop.
  2. Click Screen resolution or Display settings.
  3. At the top of the screen, select the monitor that you want to change the refresh rate for.
  4. Click Advanced settings or Display adapter properties.
  5. On the Monitor tab, click the Screen refresh rate drop-down list.

Note: This step may vary depending on your operating system and graphics card.

If the displays connected to your MST hub do not wake up after your computer goes to sleep, change the input on the monitor(s) from Auto to the correct input (for example, DisplayPort or HDMI). This prompts the monitor to send its identification data to the correct port instead of scanning for ports when the signal is lost.

After you select the correct input on the monitor(s), press the Scan button to initiate the handshake (EDID) process. For more information on the Scan button, refer to the following FAQ: http://www.startech.com/faq/mst-hubs-scan-button.

If you set the monitor to the correct video port and press the Scan button and the issue is still not resolved, you need to disable sleep mode on your computer. To disable sleep on a computer running a version of Windows, complete the following:

  1. Open Control Panel.

  2. Click Power Options.

Note: Depending on how you have the View by options set in Control Panel, you might have to click Hardware and Sound to see Power Options.

  1. Click Change plan settings for the plan in use.

  2. For both entries, change Put the computer to sleep to Never.

  3. Click Save Changes.

In order for your mouse to move properly between your monitors you must rearrange your monitors in Windows to match the physical location of your monitors on your desk. To do so, complete the following based on your operating system:

Windows 10 and Windows  8

  1. On your keyboard, press the Windows key + X and select Control Panel.
  2. Click Appearance and Personalization, then click Display.
  3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
  4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
  5. Click and drag the monitor icons to best match your physical setup.
  6. Click OK to apply the changes and close the window.

Windows 7 and Windows Vista

  1. Click the Start button and select Control Panel.
  2. Click Appearance and Personalization, then click Display.
  3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
  4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
  5. Click and drag the monitor icons to best match your physical setup.
  6. Click OK to apply the changes and close the window.

Windows XP

  1. Click the Start button and select Control Panel.
  2. Double-click Display.
  3. Click the Settings tab, which will display your monitors as numbered icons.
  4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
  5. Click and drag the monitor icons to best match your physical setup.
  6. Click OK to apply the changes and close the window.

To mirror the image from your primary monitor instead of extending your desktop, refer to the following FAQ: http://www.startech.com/faq/Windows_Mirroring_Monitors

If a DisplayPort converter with audio is not passing sound from the source to the destination, complete the following:

  1. Make sure that the DisplayPort connection on the video card is the default audio playback device.
  2. Make sure that the video card has the DisplayPort audio codec installed. If not, visit the video card manufacturer's website to find out how to update the video card driver.

To output 4K to a DisplayPort display at 30Hz, your monitor must support the resolution and refresh rate. If your monitor also supports 4K at 60Hz (DP 1.2 or higher), you may also need to set the monitor to work at 30Hz. 

To resolve this issue, use the buttons on your monitor to change the DisplayPort settings to DP1.1. For more information about how to change your monitor settings, refer to the website of the manufacturer of your monitor.

How To

To arrange extended displays on Windows 10, complete the following. 

  1. Press the Windows key+R, type desk.cpl, and press Enter. 
  2. Under the ‘Multiple Displays’ selection, select ‘Extend Desktop To This Display.’  
  3. Press ‘Identify’ to determine what number each display is assigned to. 
  4. Drag and drop each display accordingly to the physical layout on your desk.  
  5. Click the Apply button. 

Before You Buy

You may have heard of MST hubs, and have been wondering what they are, and whether or not they will work in your setup. 

So what are MST hubs?  MST hubs are devices that take one DisplayPort or Mini DisplayPort video connection, and go to many video connections, usually extra DisplayPort, Mini DisplayPort, DVI or HDMI connections.  This is accomplished through DisplayPort's MST, or Multi Stream Transport function.  MST hubs allow you to mirror / duplicate your monitors so the same window are shown on all of the monitors, or extend your desktop, so that you can have different window on each monitor.

So how can you tell if you can use a MST hub?  MST hubs require that the video card's DisplayPort or Mini DisplayPort output support DP1.2 or greater, which supports MST.  Some MST hubs also specifically require HBR2, or High Bit Rate 2 support.  HBR2 allows for higher resolutions like 4K and up.  You can check whether or not a StarTech.com MST hub requires HBR2 on the individual product pages, under the Technical Specifications tab.

There are a few other important things to note.

  • Video cards can technically support DP1.2, but not support MST or HBR2, so it is important to check with your video card manufacturer that your video card specifically supports DP1.2, MST, and HBR2 (if necessary).

Currently Mac OSX does not support MST hubs, regardless of whether or not the video card does.  This is an operating system restriction, so running Windows on an Apple computer through a program like Bootcamp will allow you to use MST hubs.

Recent versions of DisplayPort include the ability to split to multiple displays from one DisplayPort connection using Multi-Stream Transport (MST).

Although you will be able to connect the MST hub to the Mini DisplayPort (mDP) connection on your Mac, Mac OSX does not support MST for NVIDIA and Intel Graphics Processor Units (GPUs). This results in a mirrored image across the outputs of a MST hub and you will not be able to have multiple independent displays on your Mac.

The limitation of NVIDIA and Intel GPUs lies within Mac OSX. If a different operating system is used, such as Microsoft Windows via Bootcamp, you may be able to use the MST functionality of your Mac.

When you convert from DisplayPort to DVI or HDMI, it works best if you use passive video signal converters with StarTech.com MST hubs. The MST hub has the capability to convert a video signal DisplayPort to a DVI or HDMI video signal as long as a video signal converter is used to change the connection type. This is because DisplayPort 1.2 (DP 1.2) supports both MST (Multi-Stream Transport) and Dual Mode (DP++). For more information, refer to the following FAQ: http://www.startech.com/faq/displayport_converter_dp_multi_mode.

When you convert from DisplayPort to VGA, you must use an active adapter because DisplayPort uses a digital signal and VGA uses an analog signal, and the MST hub cannot convert from a digital signal to an analog signal.

Note: When you use a StarTech.com video signal converter to convert from DisplayPort to VGA, you should use the DP2VGA3. In certain circumstances, the DP2VGA2 has compatibility issues with certain VGA monitors.

Surface Dock

If you experience issues when you use a Surface Dock to connect passive video signal adapters to an MST hub, Microsoft recommends that you use active video signal converters instead. StarTech.com offers an active video signal converter for DVI monitors (DP2DVIS) and for HDMI monitors (DP2HD4KS).

Note: This issue does not apply to the Surface Pro 3 Docking Station.

You cannot use an MST hub to increase the maximum number of displays that a video card supports. For example, if your video card only supports up to three displays, your display limit will still be three displays even if you use an MST hub.

If you have multiple MST hubs connected to the same computer and are experiencing display issues, you should check your video card to make sure that it can support the number of displays that you are using in your setup.

If you use an MST hub in your setup, your video card also needs to be compatible with MST technology. For more information, refer to the following FAQ: https://www.startech.com/faq/mst-hubs-gpu-compatibility.

USB-C is a type of USB connector that is capable of supporting the following:

  • Data transfer speeds up to 10Gbps, if you use USB 3.1.
  • Bi-directional power delivery up to 100W, if both the USB host connection and the device support it.
  • Alternate modes, which deliver different types of data at different speeds. For example, DisplayPort Alternate Mode (DP Alt Mode).

If using Thunderbolt 3 over USB-C, the connection is capable of additional features. For example, Thunderbolt 3 is capable of 40Gbps of total bandwidth. For more information, refer to the following FAQ: https://www.startech.com/faq/thunderbolt-3-port-capabilities.

Not all USB-C ports or devices are capable of supporting all of the features listed above, or all of the features at the maximum capabilities. If you require a specific USB-C feature, your USB host connection, cables, and device must all support the feature that you require. For more information about whether your components support specific USB-C features, refer to the information provided by the manufacturers. 

This USB-C device requires that all of the following components support alternate modes:

  • The USB-C host connection (for example, a computer and its port)
  • The USB-C cable
  • The USB-C device (for example, a hard drive docking station)

If your host device includes a Thunderbolt™ 3 connection, this USB-C device will work with your host device.

For more information about the modes that your setup components support, refer to the information provided by the manufacturers.

Compliance and safety

Compliance letters

Safety Measures

  • If product has an exposed circuit board, do not touch the product under power.
  • If Class 1 Laser Product. Laser radiation is present when the system is open.
  • Wiring terminations should not be made with the product and/or electric lines under power.
  • Product installation and/or mounting should be completed by a certified professional as per the local safety and building code guidelines.
  • Cables (including power and charging cables) should be placed and routed to avoid creating electric, tripping or safety hazards.
*Product appearance and specifications are subject to change without notice.

Customer Reviews

(2 reviews)
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(1 Stars)

Not detecting second dell monitors as two

By: Oleg - 10/04/2019
It mirrors the first and second monitors attached to the device... it two Dell S2817Q & Dell S3219D. It sees as a single display.
| Helpful?
Matt, Customer Support on 10/15/2019 5:12:15 PM
Thank you for your feedback Oleg. We understand your disappointment in the performance of our MSTCDP122DP and we would like to help you troubleshoot. Often, the problem you're describing can indicate that your computer does not support MST capabilities. If you're using a Mac or a computer without MST support we recommend using a standard USB 3.0 to video adapter such as our USB32DP24K60 found here: https://www.startech.com/USB32DP24K60. If you're using a Windows computer with MST support, we'd be happy to look into this with you to help get this MST hub working properly for you. You can contact us at www.startech.com/support where our Technical Advisors are available 24 hours a day, 5 days a week to provide support.
(4 Stars)

Does What I Needed It To Do

By: kristi27288 - 07/26/2020
My adapter arrived Friday and have had it a week. Works just like it stated. The only problem I have is when the computer goes to sleep, I sometimes have to unplug it from the USB-C and reconnect to get it working again.
| Helpful?
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