Comment 87 for bug 589485

Fair point. Unfortunately from what I can see the xorg developers are not interested in fixing this and believe that the current behaviour is both correct and acceptable. Some of them seem to be suggesting that it is the job of the window manager/desktop environment to pass the desired settings to xrandr after receiving the monitor config from xrandr. When and if they change their mind we might be able to close this bug. In the meantime I thought I might pass on some more info...

Ubuntu developers are planning HiDPI support for the Ubuntu Linux boot experience - when dealing with GRUB2's boot-loader menu and the Plymouth boot splash screen. They are also investigating HiDPI support for Linux virtual consoles. Specifically, "Developers at this week's vUDS session will be working on a 2x version of the GRUB2 font for basic HiDPI support by just appearing twice as big, working on GRUB2 support for returning a display's physical dimensions, work out support for a scaling factor within Ubuntu's Plymouth theme, and support for a scaling factor within the console-setup font configuration."

There is also bug #1292218 which is described as "The lockscreen has correct Panel HiDPI support, but the prompt doesn't scale right now."

Some of this work might be ready for Ubuntu 14.04 "Trusty Tahr" but it is unlikely that all of the HiDPI improvements will be ready for that release.