USB-C Triple Display Docking Station - Slow Network


#1

Just like a poster from two months ago (Ry Lickliter Slow LAN speeds from dock?):

I’m having extremely slow lan speeds, like 20 mbps on a 300 mb network when connected to the PLUGABLE USB-C TRIPLE DISPLAY DOCKING STATION. Wifi is fine, only when connected to the dock do I get extremely slow speeds.

The only solution suggested at the time was to try a different network cable. I did that, and still same results.

I have a 2016 Macbook Pro w/Touchbar, just like the original poster. I just updated to the lastest DisplayLink drivers today and still same results. Any other suggestions?


#2

Hi Ed,

Sorry to hear of these issues. It looks like you worked extensively with Josh back in July on this issue and we weren’t able to reproduce the behavior any of our MacBook platforms. Still not many other reports of this, which is good overall, but frustrating trying to pin it down without being able to

Just to confirm the details, previously you were seeing the same network behavior on the 12" Retina as you’re now seeing on the MBP?

Can you please let us know any additional details about the network infrastructure, including if possible the model of any upstream network hubs, switches, or modems/gateways?

Two other questions/tests to suggest:

  1. Can you please try disconnecting from any Wi-fi networks and see if that impacts the wired throughput?

  2. Just to confirm, let’s make sure the MBP lid is open for testing, and not closed/“clamshell” mode.

I’ll look forward to updates on the above at your convenience.

Thanks!
Gary


#3

I am using the dock with a new machine (MBP) and I installed the new DisplayLink drivers. And although it has only been a couple of days, I have yet the experience the blackouts as in the 12" Retina. That’s the good news.

The bad news is that I now have a slow wired network problem. I tried disconnecting the wifi for testing, and it is slow. On speedtest.net, I get 220/22 Mbps over 5.0 GHz wifi and 13/22 Mbps over the dock alone, so it is a huge difference on the downstream. The upstream seems unaffected.

My setup is:

  • Spectrum Service
  • Arris Surfboard 6183
  • Asus AC66UB1 router
  • Plugable Dock
  • MBP Touchbar

I would expect a much faster wired connection. What is the transfer rate supposed to be through the dock?

Thank you,

Ed


#4

Hi Ed,

Appreciate the additional details!

Just to confirm, the speed test was with wi-fi disconnected and the lid of the MBP open, correct?

We’d also expect a faster wired connection. In our testing and other customer reports it’s typical that the dock will nearly saturate a gigabit connection, generally ~800-900+Mb/s depending on other USB traffic on the bus.

Haven’t seen any reports of speed issues on Asus routers, but just to cover all the bases, it might be worth updating the router firmware if a new version is available.

Also to help rule out anything related to the router (QoS, frame size, etc), connecting the dock directly to the cable modem and re-running the speed tests would a good quick test as well.

Thanks!
Gary


#5

I did test with wifi off, and the lid open. I also tested connecting directly to the Cable Modem, and I got 13/23 Mbps, same as with the router. So we can rule out the router.

I also tested another computer with wired connection to the router (no dock in between) and got 220/22, and with it directly wired to the cable modem and again got 220/22. I used the same network cables as with the dock, so we can also rule out the cables.

I could connect by wifi directly to the router and get good internet connection speeds, but when backing up (or moving large files) I would like to use the wired connection (through the dock) to obtain a faster rate than wifi provides.

  • E

#6

Hi Ed,

Thanks for confirming all that. At this point, seems like we’ve tested against almost every conceivable scenario.

If you’d like we can try having a replacement unit pre-tested on our network and sent to you.

Please email support@plugable.com (Subject: Ticket #175366) and we’ll confirm a few logistical details to get this process underway.

Thanks!
Gary


#7

I just emailed you. Thank you.


#8

I have same issue. Network speed is kinda limited to ~300 mbps. With usb-c dongle I get ~700-800 mbps on the same cable. I the other end is ubiquiti switch with newest firmware. Any suggestions? Or that 300 mbps is the limit?


#9

Hi Zygimantas,

Thanks for posting!

It appears this issue is related to Apple’s Ethernet drivers having poor performance on DisplayLink’s chips.

DisplayLink has escalated the bug with Apple (bug #31218016) and is requesting others do the same to help get the issue prioritized.

Here’s the DisplayLink thread on the issue if interested:
https://www.displaylink.org/forum/sho…

While this is under investigation, we’d be glad to send you a USB 3.0 gigabit adapter to you as a courtesy to plug into the dock. Please contact support@plugable.com and we can get things arranged.

Thanks!


#10

Thanks, for the update. I don’t need adapter, already have one. Will wait for the solution.


#11