Slow Speeds with USB3-e1000 and Mac High Sierra 10.13.6

Was noticing the speed was sub-par with this adapter recently. I know I have been updating my Mac consistently so unsure of when this change occurred, I know this adapter was working at it’s full 1gig speed before.

Right now I’m getting no more than 50-55mbits/sec transfer rates.

Driver was 1.8.0 so updated to 1.9.0. Still no change in behavior. Wondering if this is a known issue or there is something that needs to be changed to resolve.

I also have a Thunderbolt Ethernet adapter and hooked to the same cable I get the full 1GB speed I expect.

Thank you for your help as I use this for various business purposes and the speed will have me looking for another product.

During further testing I updated to version 2.11 located here:… and it seems the speed is now stuck at about 20-30mbits. I verified the NIC under system preferences is reporting 1000 full duplex under automatic settings.

Hi Jonathan,

Thank you for your post! I’m sorry you are encountering significantly slower than expected speeds with your adapter. I would like to help you troubleshoot.

This is typically either connected to a corrupted or conflicting driver installation or a potentially faulty adapter. We have a process to get the current installation(s) wiped and cleanly installed again.

  1. Could you please send me your Amazon order number? We use these to track support requests over the lifetime of the device.

  2. Are you using this in your home or another work, school, or medical environment? If at home, could you please tell me your internet service provider and promised upload and download speeds?

  3. Could you please send me your System Profile? You can gather this by opening the Apple Menu > About This Mac > System Report… and then File > Save to. Then save it to your desktop.

Please send that file and responses to the questions above to with Ticket #231721 in the subject line and I’m happy to take a look!

Thank you,

Derek Nuzum
Plugable Techonologies

Derek, thank you very much for your response. I did receive the replacement after you confirmed the existing unit was connecting at USB 2.0 speeds. I plugged in the new unit and found it reporting at USB 3.0 speeds but doing internet based speed tests ( it still performs at the 40-50Mbits/down range where testing with the Apple Thunderbolt Ethernet Adapter its at 800+Mbits/down using the same remote server (Comcast near my main city). Some additional testing I have done show that this is an issue only with the Mac to Internet communication. Doing localized file transfer tests (via SMB) from Mac to local Network Storage over a 1Gig link performs as expected (about 85-90Mbytes/sec). In the midst of all this I purchased the Anker USB 3.0 Ethernet 1Gig adapter just as a test and found a similar behavior just not as bad as the Plugable adapter. Locally it performs at the 1Gig speeds but when doing internet tests side by side to the Thunderbolt adapter it can only reach up to the 200-225Mbits range but never higher. I’m suspecting this may have something to do with the way the Mac interacts with the High Sierra OS for internet comms. I hope this helps you to get it sorted out. My next test will be with a pure Windows environment to see if the behavior is the same. Thanks for any more assistance you can provide

Hi Jonathan,

Thanks for all those details! Very good to know some more of what is going on. I sent a reply to our email communication so we can dig deeper into this.


Derek Nuzum
Plugable Technologies