#mixeddpi

All About the HiDPI Daemon

Since we started offering laptops with HiDPI screens, we’ve noticed a major challenge to users when HiDPI and LoDPI monitors are used together. We’ve received many support calls from customers on setting up their displays.  It became clear that we needed a solution available today - at least until Wayland matures to the point where it can completely replace X and is supported by all GPU manufacturers.

So, our engineer David started working on improving the HiDPI experience on X, especially for those with an NVIDIA graphics card.  Improving the multi-monitor experience ensures that when users connect a LoDPI monitor to a HiDPI enabled laptop, their displays are setup correctly with no effort on the users’ part.

How this works:

The new HiDPI service listens for display events and optimizes display settings for the best user experience possible for a variety of multi-monitor setups.  The engineering work was no trivial task requiring months of investigative work into the lower levels of the Xorg and GNOME eco-system, followed by extensive testing with numerous laptops and desktops with different graphics cards, internal screens, and monitors.  We tailored the behavior, so Intel and NVIDIA both do the right thing given their capabilities.  The end result is a seamless customer experience of using your applications across a variety of monitors of various resolutions.

Results:

You can now plug in a LoDPI external display to your Galago Pro or your HiDPI Oryx Pro, Serval WS, or Bonobo WS and expect it to just work.  The same is true when plugging a HiDPI display into any other System76 laptop.  No more complicated reshuffling every time you plug a second monitor in.

We also made it simple to switch displays between HiDPI and LoDPI.  This is especially useful for applications like GIMP and Inkscape whose toolkits do not support HiDPI and appear very small in HiDPI screens.

Whenever you have a HiDPI monitor, you’ll receive a notification that can be used to toggle between HiDPI crispness and LoDPI compatibility.  This notification can be accessed at any time in the message center.

The HiDPI daemon release is available for all System76 customers and for Pop!_OS users. It features a new and improved layout engine, the ability to use saved layouts and resolutions, and several bug fixes. The layout engine now uses saved monitor configurations to arrange displays and keeps display placement as close as possible even as they change relative (resolution) size.  

You can now set any appropriate LoDPI resolution, and the HiDPI daemon will use it. We’ve also included GSettings and a DBus API to allow other distros to create their own graphical interfaces to the daemon.   

We hope this feature will be of use to all of you as we deliver it to System76 customers and as a part of the Pop!_OS experience.  We put a lot of work into making the multi-monitor experience as seamless as possible for all our users. If you’re using a HiDPI screen on Pop!_OS or on a System76 laptop or desktop, let us know what you think.  Your feedback helps us refine and improve the experience as we prepare to release it for Pop!_OS.  

To try out the Daemon, you can find it in our PPA: system76-dev/stable The command is:

```sudo apt-add-repository -y ppa:system76-dev/stable sudo apt update sudo apt install hidpi-daemon```