The maximum resolution supported by the Plugable USBC-MSTH2 depends on the video capabilities of the USB-C port on the host computer. The adapter can support up to two external HDMI displays, but it relies on the host system to provide the available DisplayPort bandwidth over USB-C. In general, systems that support DisplayPort 1.2 over USB-C can support up to two 1920x1080 displays at 60Hz, while systems that support DisplayPort 1.4 with DSC over USB-C can support up to two 3840x2160 displays at 60Hz.
Compatibility
The USBC-MSTH2 requires a USB-C port that supports DisplayPort Alt Mode. Thunderbolt 3, Thunderbolt 4, and USB4 ports that carry DisplayPort Alt Mode are also compatible.
The adapter is compatible with supported Windows 10, Windows 11, and ChromeOS 100 or later systems.
macOS is not recommended for this product. While the adapter may function on some Mac systems, macOS does not support MST for multiple independent extended displays through this type of adapter. In most cases, both connected external displays will mirror the same image rather than extend separately.
Maximum resolution by host capability
The USBC-MSTH2 does not generate video bandwidth on its own. Instead, it splits the video signal already provided by the host computer’s USB-C port. Because of this, the maximum supported resolution depends on the DisplayPort version and bandwidth available from the host system.
In general, the expected results are:
| Host capability | Expected result |
|---|---|
| No DP Alt Mode | No video output |
| DP 1.2 host | Up to dual 1080p 60Hz |
| DP 1.4 host without sufficient bandwidth or DSC | Varies by system |
| DP 1.4 with DSC | Up to dual 4K 60Hz |
| DP 2.1 | Dual 4K 60hz |
| macOS | One extended display and one mirrored display |
Important notes about system limits
Even if a USB-C port supports DisplayPort Alt Mode and MST, the computer’s graphics processor may still limit the number of active displays or the maximum resolution and refresh rate available.
In some cases, the laptop’s built-in display counts toward the total number of displays the system can drive at one time. This means a system may not be able to support the expected external display configuration unless the internal display is disabled. On some laptops, this can be tested by using the system in clamshell mode with the lid closed, if supported by the manufacturer.
Display cable quality can also affect results. For best performance, we recommend using HDMI cables rated 2.0 (or higher) to support the resolution and refresh rate you are trying to achieve.
What is DSC?
Display Stream Compression, or DSC, is a display technology that compresses video data so higher resolutions and refresh rates can fit through a connection like DisplayPort, HDMI, or USB-C without a noticeable loss in image quality. It helps devices support demanding display modes, such as 4K at high refresh rates, when the connection would otherwise not have enough bandwidth.
How to verify your system
To estimate what resolution the USBC-MSTH2 can support on your system, check the technical specifications for your laptop, tablet, or motherboard and confirm the following:
- The USB-C port supports DisplayPort Alt Mode
- The system supports MST (Multi-Stream Transport)
- The DisplayPort version provided over USB-C is at least DisplayPort 1.2
- DisplayPort 1.4 with DSC is recommended for dual 4K display support
If the system manufacturer does not clearly list the DisplayPort version or MST support, we recommend contacting the manufacturer directly for confirmation.
Need more help?
If your system specifications indicate support for DisplayPort Alt Mode and MST, but the USBC-MSTH2 is not providing the expected display resolution or behavior, please contact Plugable support for assistance at support@plugable.com.
