Fractional scaling is practically necessary if you’re running a HiDPI display, and you want your desktop to scale uniformly to match your display. It’s always been an issue on Linux, but the latest version of the GNOME desktop has implemented a true fractional scaling feature to keep your desktop looking good.
Even though GNOME 3.26 does have fractional scaling support, it wasn’t mature enough to make the release. As a result, it’s still a testing feature that you need to enable yourself.
Where Is It Supported?
Fractional scaling was introduced informally in GNOME 3.26. As of right now, that is the absolute latest release and hasn’t made it into a lot of distribution repositories.
GNOME 3.26 will be the default desktop environment of Ubuntu 17.10, which is in its final beta. If you really need this feature, consider upgrading. Fedora 27 beta currently has GNOME 3.26, and it’s in the testing repositories of Arch Linux (not for long).
Enable Scaling Controls
Because the fractional scaling feature wasn’t entirely ready for the release, you need to enable access to it yourself. It’s not too hard. You only need to run a single command.
gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"
That command will directly interact with the GNOME Shell and enable the feature.
Set Your Scaling
Now that you have scaling enabled, you can experiment with it and find the right fit for your system.
Open your system settings and navigate to “Devices,” then “Displays.” You can choose the orientation, resolution, and, of course, the scale. Currently, the scaling ranges from 100% to 200% in 25% increments. That can possibly change in the future, but it still provides a reasonably robust set of options to fit your display.
Try different options to see what looks best and save it. Because this is integrated into GNOME itself, everything is handled through your common system interface.
That’s it! Hopefully, GNOME was able to adapt to improve your HiDPI experience.