Slow data speeds via Ethernet connection


Thank you for this great dock; it has done wonders for me having multiple screens again as well as one place for my peripherals!

Here’s my question- have you had any issues with the internet speeds on this particular dock’s Ethernet connection?

Here’s my setup-
-Apple M1 MacBook Pro

-UD-3900PDZ dock

-attached to the dock are the following-
One hdmi monitor via hdmi 1
One hdmi monitor via hdmi 2
Power adapter
MacBook Pro via the included USB-C cable that came with the dock
Ethernet cable connected to a Cisco SG 200-08P switch, which in turn is connected via Ethernet cable to a NetGear R6700v3 router

With this exact setup but connecting the Ethernet cable from the Cisco switch direct to the MacBook Pro via an Apple thunderbolt to gigabit Ethernet adapter, I am able to get my ISP’s full download speed of about 500mbs.

However, when connecting the Ethernet cable from the Cisco switch to the UD-3900PDZ dock, then connecting the dock to the MacBook Pro via the USB-C cable, the maximum download speeds drop to between 40-50mbs.

Have you any suggestions if there may be a fix available to achieve the higher speeds over Ethernet via the dock?

Thank you so much for your help!


Thank you for contacting us through our forums and directly via email, I am updating this post with relevant information from our email communication, no reply is necessary.

Working together we verified the docking station is achieving better network speeds through the speed test website, and achieving the expected network speeds with another computer indicating the issue is not being caused by a hardware failure or fault in the docking station.

We are reporting this issue to DisplayLink, the manufacturer of the network controller and hopefully network performance can be improved with either an updated driver ( provided by Apple in a system update ) or through the DisplayLink Manager App.

Thank you,

Plugable Technology