Help with UD-3900 and 2560x1080 Resolution

I recently purchased a UD-3900 docking station, however, when I connect I use the dock to connect my laptop to my UltraWide LG 34UM59-B monitor, I am only able to set the resolution to 1920x1080, not 2560x1080.

There is no difference in behaviour whether the laptop display is enabled or disabled (which makes sense, as the laptop is not going through the UD-3900). The LG monitor is the only monitor connected to the dock.

This is using the HDMI cable that came with the monitor, which is label as a high speed cable, and if I plug the monitor directly into the laptop, I can set its resolution to 2560x1080.

Am I just out of luck with this product? Would the UD-5900 provide me with the functionality I am looking for?

I appreciate any help I can get on this matter.

Edit: I should mention that I am using this as a full docking station (with Ethernet and USB devices plugged into the dock), so switching to a USB display adapter is not going to be a viable solution for me.

Hi David,

Thank you so much for reaching out to us, I am sorry that you are running into this issue, but I would be more than happy to assist!

The UD-3900 does not support resolutions higher than 1920 x 1080 on either the DVI or the HDMI port. In order to connect a display with a higher resolution, you are correct in assuming that the UD-5900 is a better match, as it allows for 4K@ 30Hz when a single display is connected via the HDMI port.

I hope this information helps! If you would like to see if it is possible to return the original docking station, and purchase a UD-5900, please reach out to us directly at, and we would be more than happy to assist.

Thank you for your patience,
Product Owner & Technical Support

Hi Everyone,

We attempted to reach out to David to provide the correct specifications and configuration information related to our UD-3900 Multi-Display Docking Station, and the difference between that unit and a UD-5900.

We did not receive a reply back, but if David or any other customers have any similar questions, please do not hesitate to reach out to us in the future and we would be more than happy to assist!

Thank you for your time,
Product Owner & Technical Support