Dual screen setup in Linux

[thomaswilliams863]

Hi everyone,

I've recently bought a Lafité Series: Aluminium Chassis: 15.6" Matte Full HD IPS LED and installed Linux on it.
I'm now looking to get a dual screen setup but wondered what experience people have with these kind of setups on this laptop running Linux? I had a fair amount of issues getting Linux to work and ended up upgrading the Kernel to a much newer version just so I could get my desktop environment to show - ideally I want to try and avoid these issues if getting some new screens. My work docking station doesn't work by standard due to driver issues, but I'm wondering if there are any docks that simply relay the video signal without the need for drivers?

The laptop has a few USB ports, thunderbold, USB C and HDMI ports. I can get the screens from PCSpecialist but does anyone know what cable setup I'll need etc. Do I need a dock in order to get dual screens? Does anyone have specific experience with support in Linux for this?

Thanks.

 

[thomaswilliams863]

Btw, for anyone who is curious, I have identified that the USB-C/Thunderbolt port does not allow display over it. This is despite having contradictory answers from staff at PC Specialist. Quite frustrating.

 

[SpyderTracks]

Btw, for anyone who is curious, I have identified that the USB-C/Thunderbolt port does not allow display over it. This is despite having contradictory answers from staff at PC Specialist. Quite frustrating.

If it’s got thunderbolt then it will allow display forwarding. There is only one version of thunderbolt 3 and it definitely carries display. That's in windows at least, I can't say weather there's support for thunderbolt in linux natively.

The easiest way to do it in windows would be to get a thunderbolt Dock with multiple display outs like this which has 2 display ports:

USB Hubs - USB C and Powered USB Hubs | Ebuyer | Ebuyer.com

Shop USB Hubs including Powered, Belkin, Multiple Port from Ebuyer. Browse USB C and Powered USB Hubs | Next Day Delivery | UK's Number 1 For Tech

www.ebuyer.com

Alternatively you could use the HDMI port and the Mini Display port to each monitor so you'd need one HDMI to HDMI (or whatever was on the monitor) and Mini DP to DP (or whatever was on the monitor).

 

[thomaswilliams863]

If it’s got thunderbolt then it will allow display forwarding. There is only one version of thunderbolt 3 and it definitely carries display. That's in windows at least, I can't say weather there's support for thunderbolt in linux natively.

The easiest way to do it in windows would be to get a thunderbolt Dock with multiple display outs like this which has 2 display ports:

USB Hubs - USB C and Powered USB Hubs | Ebuyer | Ebuyer.com

Shop USB Hubs including Powered, Belkin, Multiple Port from Ebuyer. Browse USB C and Powered USB Hubs | Next Day Delivery | UK's Number 1 For Tech

www.ebuyer.com

Alternatively you could use the HDMI port and the Mini Display port to each monitor so you'd need one HDMI to HDMI (or whatever was on the monitor) and Mini DP to DP (or whatever was on the monitor).

I've resorted to using the mini display and HDMI. From what I understand from various places online, the port may support it but doesn't mean the motherboard etc will carry display over it.


Linux supports thunderbolt displays seemleessly in the 5th version of the kernel.

 

[SpyderTracks]

From what I understand from various places online, the port may support it but doesn't mean the motherboard etc will carry display over it.

I think you may be referring to USB C rather than thunderbolt. USB C is just a data transporter unless it specifies thunderbolt over usb c or Display Port over USB C. This one specifically specifies thunderbolt which definitely carries video.

 

[Charlas]

Thunderbolt and Linux have had a troubling history, but last I tried worked fine with my Dell TB15 and TB16, just needed to make sure they had latest firmware on them.

Displayport over USB-C will only give you dp1.2 or 1.3 (so no 4k/60 without some form of compression, and that then needs interpolation drivers) and only one display (easily unless you do bandwidth limiting or compression)

Question is though, what you want Linux for (nothing personal) as I've switched 90% of my Linux need over to WSL2 nowadays (and 75% when used to be WSL1)

If you just don't want Windows, more power to you, but Linux has always been tricky with hardware that doesn't have open driver bases, and Intel ain't great at sharing (hence the TB issues till fairly resently when they 'opened' the platform, and basically gave it to usb for usb4)

USB C tends to work easier, but it's much lower bandwidth (5gbs for 3 and 10 for 3.2 versus 40gbs for tb) means it's less capable of multi display. That said one through a usb-c and one via hdmi/mini dvi would work fine for you I would think.

And yes @SpyderTracks is indeed correct, TB3 (and 2) always has video transport on it, direct from the dgpu

 

[Charlas]

Oh yeah forgot to mention, for TB3 to work you will need to 'authorise' the TB hub, it's a security thing (so not plug and pray like usb-c). To do this you either need to be running gnome 3. 30 or later, or Plasma (kde)

Failing that you will need to setup a udev to do the auth for you automatically

Nano/vim below

/etc/udev/rules.d/99-removable.rules

And add

ACTION=="add", SUBSYSTEM=="thunderbolt", ATTR{authorized}=="0", ATTR{authorized}="1"

Should make anything TB3 plugged in automatically be assigned the authorised Trust level

There's also tools like bolt that can be used if your not confident on hacking sys files