Go Back   DisplayLink Forum > DisplayLink Graphics Technology > Linux and Open Source

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-04-2017, 09:32 AM   #1
sc0p3r
Junior Member
 
Join Date: Oct 2017
Posts: 1
Unhappy DisplayLinkManager 100%CPU and 0.5s lag with StarTech USB-to-DP - Kernel 4.11

I am a (lucky?) owner of a Lenovo TP470, a laptop with a HDMI output. My previous model (TP440) allowed me to natively use 2 monitors, one connected to the mini-dp output on the laptop, the other connected to one of the video exits on the dock station.

This new model, for some reason, only shows me one monitor if I connect two at the same time (one to the HDMI on the laptop, one to any of the HDMI/DP ports on the dock station). So I bought a DisplayLink Certified USB 3.0 USB-to-DP adapter, this expensive toy: https://www.startech.com/uk/AV/USB-V...pter~USB32DP4K

The setup is to use the two Acer Predator both at 4K resolution, and not use the built-in monitor at all.

Symptoms:
When the USB to DP adapter is connected and set up, the DisplayLinkManager skyrockets at 100% of CPU. The cursor, when on the other screen connected via dock station starts blinking very fast, at the same time. The first problem is noise, as the fan will constantly be up and spinning between 50% and 100% of its max speed, for the entire day.
The second problem is a visible lag using the keyboard: writing text becomes almost impossible as simple operations such as pressing backspace will manifest on the screen really late (even 2 seconds later). Using the other screen is definitely better, but when I disconnect the USB adapter, a sensible improvement can be seen on the other screen as well.

When I disconnect the USB adapter, all is fine, and even if compiz takes a decent amount of CPU, it's not the end of the world (and I believe GNOME3 would make a difference indeed, but it does not handle HiDPI fonts/rendering as good as Unity).

Solutions:
No one
I tried any possible port and any possible combination of old and new drivers: the only mode that works is with modesetting without PageFlip. Old driver or modesetting with PageFlip make all screens fuzzy and impossible to use.
I tried XFCE4, Gnome3 and Cinnamon, but no real difference can be seen: especially Gnome3, becomes even harder to use considering it's all an animation when you hit any corner

Setup:
- Ubuntu 16.04 with recent kernel 4.11 (NVME drives are handled much better after 4.10)
- ThinkPad Ultra Dock as dock station https://www3.lenovo.com/gb/en/access...W/p/40A20090UK
. - Two Acer Predator 4K monitors, one connected via DP on the dock station (there are two, there seems to be no difference) and one connected via Startech USB adapter (either directly on the laptop USB 3.0 port or via the USB 3.0 port on the dock station)
- DisplayLink USB Graphics Software for Ubuntu 1.3.54
- X.Org X Server 1.18.4 / Release Date: 2016-07-19


I understand this is an extreme setup, but I am really stuck because, if I cannot make it work, I will have to go back to Windows 10 which is something I really don't want to... I would more happily re-use my old laptop rather, wasting approx 1400 $ worth of equipment (TP470 has a 1TB NVME hd, they are pretty expensive).

Of course, I can provide you any type of log/trace you want, just ask what you need. Being a corporate laptop, I need some time to take them, but I will. There are other colleagues in my situation (we, as corporate, sponsor more Linux than Windows, and we reached a deal for 4K monitors recently) but I am the only one who really make use of two 4K monitors at the same time, for my job.

Begging for help
sc0p3r is offline   Reply With Quote
Old 10-06-2017, 06:50 PM   #2
mlukaszek
Senior Member
 
mlukaszek's Avatar
 
Join Date: Feb 2010
Posts: 313
Default

X don't really like the case when the built-in screen is off. Is this working better when you keep it enabled?

Cheers,
Michal
mlukaszek is offline   Reply With Quote
Old 10-10-2017, 08:52 PM   #3
compuguy
Junior Member
 
Join Date: Oct 2017
Posts: 1
Default

Quote:
Originally Posted by sc0p3r View Post
I am a (lucky?) owner of a Lenovo TP470, a laptop with a HDMI output. My previous model (TP440) allowed me to natively use 2 monitors, one connected to the mini-dp output on the laptop, the other connected to one of the video exits on the dock station.

This new model, for some reason, only shows me one monitor if I connect two at the same time (one to the HDMI on the laptop, one to any of the HDMI/DP ports on the dock station). So I bought a DisplayLink Certified USB 3.0 USB-to-DP adapter, this expensive toy: https://www.startech.com/uk/AV/USB-V...pter~USB32DP4K

The setup is to use the two Acer Predator both at 4K resolution, and not use the built-in monitor at all.

Symptoms:
When the USB to DP adapter is connected and set up, the DisplayLinkManager skyrockets at 100% of CPU. The cursor, when on the other screen connected via dock station starts blinking very fast, at the same time. The first problem is noise, as the fan will constantly be up and spinning between 50% and 100% of its max speed, for the entire day.
The second problem is a visible lag using the keyboard: writing text becomes almost impossible as simple operations such as pressing backspace will manifest on the screen really late (even 2 seconds later). Using the other screen is definitely better, but when I disconnect the USB adapter, a sensible improvement can be seen on the other screen as well.

When I disconnect the USB adapter, all is fine, and even if compiz takes a decent amount of CPU, it's not the end of the world (and I believe GNOME3 would make a difference indeed, but it does not handle HiDPI fonts/rendering as good as Unity).

Solutions:
No one
I tried any possible port and any possible combination of old and new drivers: the only mode that works is with modesetting without PageFlip. Old driver or modesetting with PageFlip make all screens fuzzy and impossible to use.
I tried XFCE4, Gnome3 and Cinnamon, but no real difference can be seen: especially Gnome3, becomes even harder to use considering it's all an animation when you hit any corner

Setup:
- Ubuntu 16.04 with recent kernel 4.11 (NVME drives are handled much better after 4.10)
- ThinkPad Ultra Dock as dock station https://www3.lenovo.com/gb/en/access...W/p/40A20090UK
. - Two Acer Predator 4K monitors, one connected via DP on the dock station (there are two, there seems to be no difference) and one connected via Startech USB adapter (either directly on the laptop USB 3.0 port or via the USB 3.0 port on the dock station)
- DisplayLink USB Graphics Software for Ubuntu 1.3.54
- X.Org X Server 1.18.4 / Release Date: 2016-07-19


I understand this is an extreme setup, but I am really stuck because, if I cannot make it work, I will have to go back to Windows 10 which is something I really don't want to... I would more happily re-use my old laptop rather, wasting approx 1400 $ worth of equipment (TP470 has a 1TB NVME hd, they are pretty expensive).

Of course, I can provide you any type of log/trace you want, just ask what you need. Being a corporate laptop, I need some time to take them, but I will. There are other colleagues in my situation (we, as corporate, sponsor more Linux than Windows, and we reached a deal for 4K monitors recently) but I am the only one who really make use of two 4K monitors at the same time, for my job.

Begging for help
Ignore what I previously posted. Based on what Lenovo documents for its TB3 dock and the dock you currently have (ThinkPad 90W Ultra Dock), can only drive one 4k monitor at 60 Hz, and one 1920x1200 via DVI-D, or two 4k displays at 30 hz each (source: https://support.lenovo.com/us/en/solutions/pd029622). You might have better luck looking into a thunderbolt 3 docking solution (the T470, T470s have a type-c/Thunderbolt 3 port).

Last edited by compuguy; 10-10-2017 at 09:05 PM.
compuguy is offline   Reply With Quote
Reply

Tags
cpu, usb

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 02:46 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.