Introduction
The StarTech.com MSTDP123DP is a 3-Port DisplayPort 1.2 Multi-Stream Transport (MST) Hub designed to connect multiple DisplayPort monitors to a single DisplayPort output on your Windows computer. This device allows for extended or mirrored display configurations, enhancing productivity by utilizing up to three independent displays. It supports resolutions up to dual 4K at 30Hz and 1080p at 60Hz, depending on the system's capabilities and bandwidth allocation. This MST Hub is compatible with DisplayPort 1.2 / HBR2 / MST enabled systems and is intended for use with Windows operating systems only.
Product Overview
Familiarize yourself with the components of your StarTech.com MSTDP123DP 3-Port DisplayPort 1.2 Splitter.

Image: Front view of the StarTech.com MSTDP123DP 3-Port DisplayPort 1.2 Splitter, showing three DisplayPort output ports labeled "OUTPUT".

Image: Rear view of the StarTech.com MSTDP123DP 3-Port DisplayPort 1.2 Splitter, showing the power input port and the integrated DisplayPort input cable.

Image: Diagram illustrating the dimensions of the MSTDP123DP hub and the included universal power adapter with various regional plugs.
Setup Instructions
Follow these steps to set up your MST Hub and connect multiple displays.
- Verify System Compatibility:
Ensure your computer's video card supports DisplayPort 1.2 / HBR2 / MST. You can check your video card model in Windows Device Manager (Right-click the Windows icon or press Windows key + "X", then select Device Manager, and expand "Display adapters").
- Connect the MST Hub to your Device:
Plug the integrated DisplayPort cable from the MST Hub into a compatible DisplayPort output on your computer, laptop, or tablet.
Video: This video demonstrates the physical connection of the MST Hub to a laptop's DisplayPort output and the subsequent power connection.
- Connect Power to the MST Hub:
Plug the included power adapter into the MST Hub's power input port, then connect the power adapter to a wall outlet.
- Connect Displays to the MST Hub:
Plug your DisplayPort cables (or DisplayPort adapters/converters for HDMI, VGA, or DVI monitors) into the DisplayPort output ports on the MST Hub. Connect the other end of these cables to your monitors.
- Power On Your Device:
Power on your computer and log in to your Windows operating system.
Operating Instructions: Display Configuration
After connecting your displays, you will need to configure them within Windows Display Settings.
- Access Display Settings:
Right-click on an empty area of your desktop and select "Display settings".
- Arrange Displays:
In the Display settings window, you will see representations of your connected monitors. Click the "Identify" button to see which number corresponds to each physical monitor. Drag and drop the monitor representations to match their physical arrangement on your desk.
- Select Display Mode:
Under "Multiple displays", choose your desired display mode:
- Extend these displays: Each monitor acts as a separate workspace, allowing you to spread applications across multiple screens.
- Duplicate these displays: All monitors show the same content.

Image: Visual representation of Extended Mode (independent content on each display) and Mirror Mode (same image on multiple displays).
- Apply Settings:
Click "Apply" to save your display configuration.
Resolution and Bandwidth Considerations
The maximum resolution output depends on your system's video card capabilities and the total bandwidth used by all connected displays. MST technology shares video bandwidth across all attached displays.

Image: Table detailing various video output resolutions (e.g., 1920x1200@60Hz, 2560x1440@60Hz, 3840x2160@30Hz) for three displays and their corresponding total bandwidth percentage usage. Note that 4K@30Hz is supported on two displays, with the third display at 1080p@60Hz or lower.
Specifications
| Feature | Detail |
|---|---|
| Model Number | MSTDP123DP |
| Brand | StarTech.com |
| Number of Ports | 3 (DisplayPort Output) |
| Input Connector | 1x DisplayPort 1.2 Male |
| Output Connectors | 3x DisplayPort 1.2 Female |
| Max Digital Resolutions | 2x 4K 30Hz + 1x 1080p 60Hz (dependent on GPU) |
| Compatible Devices | PC (Windows Only) |
| Dimensions (L x W x H) | 15.2 x 3.1 x 0.8 inches (approx.) |
| Item Weight | 0.22 Pounds (approx.) |
| Power Source | External Power Adapter (included) |
| Certifications | RoHS, CE, FCC, VESA, DisplayPort |
Troubleshooting
- No Display or Incorrect Resolution:
- Ensure all cables (DisplayPort and power) are securely connected.
- Verify that your computer's graphics card supports DisplayPort 1.2 and MST.
- Update your graphics card drivers to the latest version from the manufacturer's website.
- Check Windows Display Settings to ensure displays are detected and configured correctly (extended or duplicated).
- Reduce the resolution of one or more displays if you are exceeding the total available bandwidth of your graphics card or the MST Hub. Refer to the Resolution and Bandwidth Considerations section.
- Displays Not Detected:
- Restart your computer after connecting all displays.
- Ensure the MST Hub is receiving power.
- Test each display individually to confirm they are functional.
- If using DisplayPort to HDMI/VGA/DVI adapters, ensure they are active adapters and compatible with DisplayPort 1.2.
- Intermittent Display Signal:
- Check for loose cable connections.
- Ensure DisplayPort cables are of high quality and meet DisplayPort 1.2 specifications.
- Avoid excessive cable lengths.
Maintenance
To ensure the longevity and optimal performance of your MST Hub, consider the following maintenance tips:
- Keep the device clean and free from dust. Use a soft, dry cloth for cleaning.
- Avoid exposing the device to extreme temperatures, humidity, or direct sunlight.
- Ensure proper ventilation around the device to prevent overheating.
- Handle cables carefully to prevent damage to connectors and ports.
Warranty Information
The StarTech.com MSTDP123DP 3-Port DisplayPort 1.2 Splitter is backed by a 3-year warranty. For detailed warranty terms and conditions, please refer to the official StarTech.com website or contact their customer support.
Technical Support
StarTech.com offers free lifetime technical support for this product. If you encounter any issues or require assistance with installation or operation, please visit the StarTech.com website for support resources, FAQs, and contact information for their technical support team.
Website: www.StarTech.com