XQuartz (the X11 server for OS X ) doesn't support Retina/HiDPI resolution and, last I checked, has no plans to.
The best way to get native Retina/HiDPI support on OS X would be to build using GTK+ 3 using the native OS X backend instead of X11... however it's likely that HiDPI fixes will be needed before this works fully.
XQuartz (the X11 server for OS X ) doesn't support Retina/HiDPI resolution and, last I checked, has no plans to.
The best way to get native Retina/HiDPI support on OS X would be to build using GTK+ 3 using the native OS X backend instead of X11... however it's likely that HiDPI fixes will be needed before this works fully.