Increase in speed not seen after installation, USB3 ethernet adapter.

After installing the driver from pluggable website and USB3 ethernet adapter, speed still only 100Mbps (Windows 8.1). Shouldn’t I be seeing 1000Mbps? Device Manager says “Speed and Duplex” set to “Auto negotiation”. Adapter is installed directly into usb3 port on laptop (not through a hub).

Hi Charles,

Thank you for contacting us about your USB Ethernet adapter. I’m sorry you are not seeing the speeds your are expecting.

There are many variables that can affect speed. To help isolate the issue, could you please answer a few questions?

  1. Are you testing for speed against another computer, or going by the speed in the properties window?

  2. What kind of network are you connecting on? Is it a home network, an office network, or an institutional one, like a hospital or university?

  3. What is between the adapter and the gateway (cables, switches, hubs, etc.)?


Plugable Support


I decided to double check the cables I am using and discovered that one of them is not up to par. This I noticed when plugging it in between the modem and a 10/100/1000 switch. The switch showed a steady yellow light for the cable, which indicates a 100Mbps speed. I replaced the cable and now a green light appeared, which indicates a 1000Mbps speed.

I had been using the so-so cable with the plugable device. I kept everything else the same, used the new cable, and things are good now. First, I am seeing a better listing in the properties window (below). Also, I have observed a few record results with OOKLA.

In sum, it was a so-so cable that was causing the trouble. Had I figured that out sooner, I would not have troubled you.



I should have mentioned that I answered David’s questions in an email. Although the questions were very helpful, it turned out to be a hardware (network cable) issue.

Thanks for letting us know you solved it!

Please contact us if you have any other issues.