The M1 and M2 models can drive 4 total displays: 3 external 4K panels and the laptop panel. The XE model can drive 3 total displays: 2 external 4K panels and the laptop panel. A 4th panel can be added to the XE through daisy-chaining. The Ir14 can drive 4 total displays: 2 external 4K panels, a 1080p panel, and the laptop panel. Finally, the NX models can drive up to 4 external 4K displays.
Open system settings and then click
Displays. The interface will appear as shown when no external displays are attached. Use this a your preferred interface for setting your display configuration. This overlaps with the Nvidia tool which is discussed next.
Kubuntu Focus Video Sync Utility. Finally, and perhaps most importantly, it encourages one to write an
xorg.conf file, which can break hot-plugging of displays. However, there are some useful advanced settings that are not available elsewhere. We just recommend that you decline to write that
xorg.conf file when asked!
The M1 and M2 models can easily drive up to four displays with the discrete RTX GPU: the laptop QHD or 1080p LCD, and three external panels using mDP, USB-C, HDMI, and Thunderbolt. All external displays can be at least 4K resolution.
The XE models can drive up to four displays with the integrated Iris Xe GPU: the laptop 1080p LCD, and three external panels using HDMI and Thunderbolt. All external displays can be at least 4K resolution. One must use Thunderbolt Daisy Chaining to attach the 4th display.
The NX models can drive up to four displays with the integrated Iris Xe GPU: all external panels using 2 x USB-C ports, HDMI, and mDP. As with the others, the Thunderbolt port may be daisy-chained to drive more than a single panel. All panels can be at least 4K resolution.
The Ir14 model can drive up to four displays with the integrated UHD GPU: external 4K displays, a 1080p display, and the laptop panel concurrently.
If your monitor does not have matching input, you can convert the signal. You may, for example, use a converter cable to attach a DisplayPort input on a display to the USB-C output on the system. However, it is best to avoid converter cables when you can. With any cable, check the rated capacity to ensure it can drive the display at the resolution you want. Also, remember that HDMI can transport high-quality audio, and this can be useful in certain situations.
USB-C and mDP outputs have the highest capacity and can drive monitors up to 8k @ 60 Hz, while the HDMI output can drive a monitor at 4K @ 60 Hz. Available options are determined by the output capabilities from the laptop and the capabilities of your monitors. If, for example, you attach a 1080p @60 Hz monitor, the highest resolution you may select will be 1920 x 1080.
As you attach the cables, the displays will appear on-screen. You can also attach the cables without the settings window open. In this situation, you will be prompted to configure each monitor as you connect each cable.
Once all displays are added, you will want to move them to the desired location. We suggest placing the laptop to one side on a stand and aligning the displays to the bottom edge. Click on
Identify to ensure you have them in the proper order. Make sure all the displays are
Enabled and the laptop panel is set as the
Primary display. Then click
Once you have the displays positioned, you should be able to sweep your cursor across all displays from left to right. Increase cursor speed as needed. If the cursor does NOT switch smoothly between screens, return to the display settings to adjust as needed.
High-DPI (HiDPI) displays have substantially higher pixel density than 96 Dots Per Inch (DPI). Most desktop 4K monitors are HiDPI, as are QHD 15.6 or 17.3" laptop displays. This higher density can cause text or buttons to display smaller than desired. Although upcoming KDE versions work better with display scaling, we have found that setting the font DPI is more reliable for KDE 5.24 LTS.
System Settings > Fonts > Fonts. Then set the font DPI; on a 28" 4K display, we have found 144 DPI to be a good choice. Then logout and back in, and you should see larger window titles, text, and other graphics.
Sometimes, GTK apps like Google Chrome or Meld refuse to follow the DPI settings. The following steps almost always fix this issue, and the changes remain even after logging out:
xsettingsdand press return.
Control + Cto exit the xsettingsd process
It is best to disable displays by visiting
System Settings > Displays interface. Unplugging a display has the same effect, but it takes longer. In either case, the system moves application windows to the remaining visible displays.
We have tested the WavLink WL-UG69DK1 Rev B1 universal docking station. It performs best when one connects to it with USB-C or Thunderbolt. The USB-A port can be used for a few lower resolution displays; however, because of limited bandwidth, it can become laggy and require lots of CPU power when attaching more displays. The best driver to use should be the evdi-dkms package,
sudo apt install evdi-dkms. At the time of writing, however, the driver wasn't compatible with kernel 5.17, and we had to use the newest version available from Synaptics. You may also visit the official support page, although we found that driver to often be older.
While we have not tested other docking stations, those that use the
evdi-dkms or Synaptics drivers should likely be compatible. We encourage you to ensure hardware is compatible with Linux before committing to a purchase. Usually, a web search will provide lots of guidance. Please write email@example.com if you need further assistance.
One may tile a window by "pushing" it into a screen edge. To change this behavior, click on
System Settings > Workspace Behavior > Screen Edges and adjust as desired. Remember, you can always click
Defaults to restore the default settings.
Remember, there is a window behavior modifier key, which is
Alt by default. One may, for example, press this key and then click-and-drag anywhere in a window to move it. This is very handy, especially if the window is partially off screen.
Unfortunately, many applications have keyboard shortcuts that require the
Alt key. To allow these shortcuts, we recommend you change the modifier key to Meta. To do this, click on
System Settings > Window Management > Window Behavior > Window Actions tab and then select
Meta as shown in the image.
Virtual Network Computing can be done with the help of KRFB, and KRDC which is useful when working on the same network as many other machines.
A more in-depth article can be found on BinaryTides showing how to install and setup a VNC
This consideration ONLY applies to systems with Nvidia GPUs, like the M1 or M2. It does NOT apply to Intel-only systems like the XE, NX, or Ir14.
Focus systems offer to turn off Nvidia GPUs when using battery and Intel graphics. This extends the battery life significantly, and it is the preference of many users. When you do this, however, not all the external display ports remain available. The only way to restore these ports is to reboot the system.
Intel (Power-Save Mode) and the M2 GEN 3+ models, one can add one additional display using USB-C. With the right equipment, you may be able to daisy chain addition displays. Otherwise, if you require the maximum number of external displays, please switch to Nvidia Performance mode. Other options include using Hybrid GPU (On-Demand Mode) which can reduce responsiveness, or adding a display dock.
Q: I would like to run multiple displays with the iGPU. Is this possible?
A: Yes. If you are using a system without a discrete GPU, any mDP, HDMI, or USB output should work. If you are using an M-series laptop and using the Intel iGPU, you may attach an addiitonal display through the USB-C port. Another option is to use a universal Docking Stations to drive external 1080p or 4K displays. However, be careful, as these require a fast connection (Thunderbolt is preferred), and some may require drivers that have high overhead.
Q: When I plug in an external display everything slows down. What is the problem?
A: This can happen when you are using the Hybrid GPU (On-Demand Mode). This mode uses the Intel GPU to drive all displays slow performance. As mentioned elsewhere, we recommend this mode only when you want to maximize VRAM for GPGPU purposes. But sometimes one can forget to switch back.
To fix this, visit the GPU widget in the system tray and select
Switch to Nvidia GPU (Performance Mode). After rebooting, your desktop interface should run much more smoothly.
Q: When I booted, my external displays do not work. What could be happening?
A: There are two likely causes. First, you may be running
Intel (Powersave mode). Switch to
Nvidia (Performance mode) and your displays should return (see M2 External Displays for more detail). If you are already running in
Nvida (Performance Mode) and the displays are still not showing up, the DKMS modules may not be updated correctly. Please try running
sudo dkms autoinstall and follow the instructions. Install headers if you are requested. Once complete, reboot and the multi-display support should return.
Q: I was previously able to connect an external monitor. Now that same monitor is not recognized. What I can I do to fix this?
A: The file
/lib/modprobe.d/nvidia-kms.conf contains a setting for Nvidia GPUs. This can get changed during an driver update. You can edit it using
sudo kate /lib/modprobe.d/nvidia-kms.conf (use your preferred text editor like
editor). Then ensure the
modset=0 is the final portion of the line as presented below.
If you changed the file, sign-out and then sign-in again to restart the X-server (although a reboot might be needed - ed), after which your monitor should be recognized. Thanks to Matt K. for sharing his research.
This is a partial revision history. See the
git repository for all entries.
2023-07-09 33ece8e2Add advice on GTK app scaling
2023-06-19 a7af817bExpand display settings section
2023-06-19 a7af817bUpdate dGPU schematic
2023-04-25 19f0fa02Revise Intel graphics, Ir14 sections
2023-04-16 b2a98ac2Fix minor grammar and spelling errors
2023-04-16 1bc15058Revise iGPU advice
2023-03-16 189ca8aeAdjust XE advice per Gen 2
2022-08-30 7db76c5eUpdate main image to be more Jammy
2022-08-08 89994f16Add VNC setup details
2022-07-19 3b5c2287Update content for 22.04
2021-10-10 5728326eReformat to 2-column
2021-09-22 dc862884Update link and headline colors
2021-09-14 93b1d395Add Wavlink docking station details
2021-08-23 681261b4Review and update codeblocks
2021-07-28 1b9cf29bRevise units to have a space after number
2021-04-29 d21d0881Add hint to reset on-demand mode
2021-03-04 6aad5dc8Add specs for monitor support
2020-10-31 9c3ef96dFirst publication
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