I've recently purchased a Dell UP2715K which has a resolution of 5120x2880 and have installed ubuntu 15.10 to go with it. The UP2715K is connected to a GeForce 960 GTX (2 displayport cables since 1 cable alone would not handle the bandwidth), and as such the display is actually seen as two 2560x2880 monitors, hardware-wise.

Ubuntu installs just fine, and after installing nvidia drivers the display ran at its native 5K resolution + HiDPI scaling works, and the image is just wonderful. However, ubuntu still seems to think there are two displays for a few purposes, and I still have two small issues:

  • top menus don't go across the whole screen

  • maximizing windows only leads to them occupying one side of the screen

Question is: How can I fix these issues? Is there any way the OS will really only see one big 5120x2880 screen?... I tried poking around with display settings + nvidia configs but didn't manage so far...

Edit: Unfortunately the maximization issue also means I cannot view content such as netflix in true fullscreen... which is rather frustrating. No success so far, tried several distros too (Kubuntu, Mint, ...)

  • Did something similar a while back (12.04), first with Xinerama, then TwinView (for Nvidia). Not sure it still works (now on a single 1440p ultrawide), but worth looking at. Some instructions : help.ubuntu.com/community/XineramaHowTo Apr 5, 2016 at 21:06
  • I can not imagine how such an old distro should handle such a brand new challenge: Any >4K Monitor really asks for Ubuntu 18.x and Wayland to be tested. This might help a lot since High DPI is a quite recent challenge to the developers. Jul 1, 2018 at 9:15

2 Answers 2


The driver does see the monitor as one screen but it also tells the window manager that there are two independent panels, which the window manager then uses when maximizing windows.

You can enable the Video Wall script in KDE to make it use the whole monitor under some circumstances, like for video players, without using Xinerama. See the answer here.


Yes, and no.

To make the basic system see one large screen, you will have to enable Xinerama (the NVidia documentation is incorrect in this sense, and states you must disable it).

However, even with Xinerama enabled and basic functionality working correctly, you will still have issues with some things not wanting to work properly, such as attempting to view flash videos full screen, or some games will have issues, only being able to perform full screen on half of the monitor; or just not working at all.

Part of the problem is Xorg. There are some new features in the latest version of Xorg included in Ubuntu 16.04, which should help with this, but which are still unstable and very difficult to configure, as well as having the problem of not retaining configuration across restarts of the Xorg server. Then there are the drivers. The NVidia drivers are just not as good as they claim to be, and just don't keep in line with kernel and Xorg development.

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