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When we connected the Samsung Galaxy S8 with the Plugable USB-C Docking Station with Power Delivery / Charging (Model UD-CA1) in a previous review, we noticed an interesting phenomenon.

 

The Samsung Galaxy S8 could recognize the Ethernet, audio, and multiple storage drives connected to the Plugable USB-C Docking Station with Power Delivery / Charging (Model UD-CA1).

   

However, looking at the SanDisk Type-C Flash Drive and Samsung Portable SSD T3 connected to the Plugable USB-C Docking Station with Power Delivery / Charging (Model UD-CA1), surprisingly all the drives were enumerating at USB 2.0 speeds even though they are USB 3.1 Gen 1 (5 Gb/s) drives. Even the Realtek USB 3.0 card reader chip was showing up as a USB 2.0 device.

  

We could see that all the USB devices in or connected to the Plugable USB-C Docking Station with Power Delivery / Charging (Model UD-CA1) were showing up downstream to the USB 2.0 hub inside the Samsung Galaxy S8.

 

If we connected the Samsung Portable SSD T3 directly to the Samsung Galaxy S8, we find a different story.

Here we see that the Samsung Portable SSD T3 is now enumerating as a USB 3.1 Gen 1 (5Gb/s) device behind the USB 3.1 Gen 1 hub inside the Samsung Galaxy S8.

  

We also connected the Samsung Galaxy S8 to the Dell USB-C to HDMI/VGA/Ethernet/USB 3.0 Adapter (DA200) which contains an embedded USB 3.1 Gen 1 hub. Again, all the USB devices inside the Dell USB-C to HDMI/VGA/Ethernet/USB 3.0 Adapter (DA200) were enumerating as USB 2.0 devices with the Samsung Galaxy S8.

 

Apparently, any device like a dock which has a USB 3.1 Gen 1 hub is automatically downgraded to USB 2.0 speeds by the Samsung Galaxy S8  which is an unusual behavior that also isn't communicated clearly to the user.

When we connect the same devices as above to the LG G5, we can see more expected behavior where all devices enumerate as USB 3.0 devices. For example, here we can see that the USB 3.1 Gen 1 devices inside the Dell USB-C to HDMI/VGA/Ethernet/USB 3.0 Adapter (DA200) enumerate correctly at USB 3.1 Gen 1 speeds.