Mouse and keyboard lag

Just bought a UD-3900 to replace a Thinkpad Basic USB 3.0 dock because the keyboard and mouse had a painfully slow lag when I connected it to my work laptop (Lenovo ThinkPad P50 running Win7). I had no issues when using the dock with my personal PC (Dell Inspiron running Win10).

I am experiencing the same issue now with the UD-3900, except I notice the lag goes away if I use the laptop keyboard and (wireless) mouse. This is not a solution, though, since the reason I want the dock is so I can use my full-size keyboard and my larger monitors.

This seems to place the fault with something wrong on my laptop, but I have updated my USB and display drivers to no effect, and am out of ideas.

I see others on these forums reporting the same issue, and the response seems always to be “send a PlugDebug file”, but there is never any follow-up as to what Plugable support found, nor any suggestions for others who may be experiencing the same issue.

Hi Carl,

Thanks for reaching out to us, I am sorry the keyboard is not working as expected.

A few known issues may create input lag when the keyboard is connected to a USB hub.

For wireless keyboards, USB 3.0 controller and devices can produce broadband interference in the 2.4Ghz ISM radio band used by most wireless keyboards. This interference can slow or skip key presses on the keyboard. Moving the keyboard closer to the receiver will normally reduce or resolve this issue.

For wired keyboards, if the keyboard controller is incompatible with the USB hub this can cause input lag or connectivity problems. Testing with a keyboard from another manufacturer will help to narrow down the issue to the keyboard specifically.

Potentially software issues may create input lag as well, this will be much harder to narrow down.

Please let me know if you have a wired or wireless keyboard, and if it suffers lag when connected directly to the computer with the docking station disconnected. Please also test with the keyboard connected directly to the computer and connect the docking station to another USB 3.0 port see if this affects the behavior as well and let me know if just having a docking station attached ( but without the keyboard connected ) causes this behavior.

As to the unanswered questions, we try to post answers when we find them, however sometimes we do not get a reply back from the affected users.

Thank you,

Plugable Technologies

Hi Pat, thanks for your prompt reply.

The keyboard and mouse I’d like to use are both wired. As I mentioned, everything works perfectly when the USB-A end of the hub input is connected to my Dell PC instead of my laptop.

To answer your specific questions:

  • I experience no lag when the keyboard and mouse are connected directly to the laptop with the docking station disconnected (laptop display only).
  • I experience no lag when lag with the keyboard and mouse connected directly to the laptop with the docking station connected (display to 2 Acer R240HY).
  • I experience no lag using the laptop keyboard and wireless mouse with the docking station connected (laptop display and 1 Acer R240HY)
  • I experience no lag using the wired keyboard and mouse via the docking station (laptop display plus 2 Acer R240HY)

However, if I close the laptop lid, dropping down to the 2 large monitors, things slow to a crawl. A simple action such as creating or replying to an email takes ~10 minutes to render the email window. If I open a large program such as MS Word or Visual Studio, it will hang at the splash screen apparently indefinitely. But typing in an open window acts like normal, and the mouse responds normally.

If I open the laptop lid again, though, whatever window was rendering or program startup completes immediately, as if it had been waiting for the laptop display to become available.

I may have messed something up with all my fiddling with the display settings. I can no longer reproduce the original problem where everything was “normal” but just slow.

It sounds like keeping the laptop lid open is a workaround, but I don’t have room on my desk for all 3 displays, and I don’t want to have live desktop space on that display if I put it somewhere else.

Any ideas?


I should clarify that what I want is to be able to simply move the USB-A end of the hub/docking station back and forth between my personal PC and my work laptop depending on what I’m doing, leaving everything else the same.

Hi Carl,

Thank you for the additional information, this is very odd behavior!

Based on your description of the behavior, our next step is to get some additional information from your system.

If you would, please keep the dock connected and both monitors attached, and the lid open. Attach the output of our diagnostic utility PlugDebug ( ) to an email to “” with subject line “Ticket #237427 - Attention Pat” as this will allow us to examine some log files from your system to help determine the next steps.


Plugable Technologies

Hi Pat,

I had to get my laptop reimaged due to another issue, and when I got it back (now with Win10) it is working properly with the dock.

Sorry we weren’t able to identify the issue for the benefit of others who come looking for answers, but glad to be up and working again. Thanks for your help.

Hi Carl,

Thank you for letting me know, I am glad everything is working for you!

I will be marking this thread as closed, if you have any additional questions please feel free to start a new thread or contact our support email at

Thank you!

Plugable Technologies