3 4K monitors using UD-ULTC4K on Microsoft surface pro 9

Hi there I have just purchased the UD-ULTC4K and am connecting 3 Samsung LU28R550UQUXEN 4K monitors to a brand new Microsoft surface pro 9 windows 11 16GB ram i7 with intel Iris graphics. 2 monitors display 4K at 60hz the 3rd only at 30hz I’m connecting to my surface with the supplied cable. Do I need to upgrade the cable to a thunderbolt 4 cable to overcome this? As the supplied cable is usb C.

Apologies if I’m doing something wrong.




Thank you for contacting us, I am sorry this is not working as expected and I am happy to help!

When you have a moment please let me know which port is connected to the 4K 30Hz display. Each pair of DisplayPort and HDMI output is labeled as “Display #” just above the port-pair.

Additionally, are the displays connected with HDMI to HDMI cables, or DisplayPort to DisplayPort cables?

The supplied USB-C data cable supports the bandwidth required for 4K 60Hz displays, no additional cables are necessary.

The UD-ULTC4K with three HDMI and three DisplayPort outputs can support three 4K 60Hz displays when paired with a computer that supports USB-C DisplayPort Alternate Mode version 1.4 with HBR3 (High Bit Rate version 3) and DSC (Display Stream Compression). Unfortunately Microsoft’s support information does not specify the versions of these features for any of the Surface lines of systems.

I do not have a Surface Pro 9 on hand to test with at the moment but I am trying to get a hold of one to verify if the system can support three 4K 60Hz displays, or if it is limited to 4K 30Hz for the “Display 1” output port.

Thank you for these additional details, I look forward to your reply and I will update this thread as I get testing results for this computer and docking station.

Plugable Technologies


Today I received an update, we tested the UD-ULTC4K with the Microsoft Surface Pro 9 and three 4K 60Hz displays were detected and functional at 3840x2160 resolution and 60Hz refresh rate, however it required manually setting the displays to 60Hz refresh rate for one of the display configurations.

When you have a moment please let me know which output port on the docking station is connected to the 30Hz display.

We can manually set the display refresh rate by performing the following:

  1. Connect all three external displays to the docking station, then connect the docking station to the computer using the included USB-C data cable
  2. Right-click on the desktop and select “Display Settings” from the pop-up menu
  3. Scroll down to the bottom of the window and select “Advanced Displays”
  4. In the top-right of the window select the drop down menu for each display and then select the refresh rate and set each display to 60Hz.

Please let me know if one of the displays does not show an option for 60Hz, and which port it is connected to on the docking station.

Thank you,

Plugable Technology

Hi Pat,

Sorry been away on a course. I have manually configured all displays to 60hz and works perfectly now. Just a quick question I have configured the displays this way:-

1 surface pro internal display on intel iris XE
2 1st Samsung 28” at 4K intel Iris XE
3 2nd Samsung 28” at 4K on pluggable as graphics driver
4 3rd Samsung 28” at 4K on pluggable as graphics driver

Works seamlessly now

Pic for reference and thank you for your assistance :+1:t2::+1:t2:


That’s great to hear, and I am glad all three displays are working as expected now!

If you have any additional questions, or if there is anything else I can do to help, please feel free to start a new thread, or contact our support via email at ‘support@plugable.com’.

I will go ahead and close this thread.

Thank you,

Plugable Technology