X Server 1.13 has better hybrid graphics support
X Server 1.13 has been released by the X.Org project with improved support for hot-pluggable, hybrid graphics hardware. This includes DisplayLink hardware which is connected using USB, and hybrid graphics technologies such as NVIDIA's Optimus, a feature that is primarily used in notebooks. Optimus enables the dedicated GeForce GPU on demand and works with the GPU in the CPU.
To configure hot-pluggable graphics hardware, the developers have extended the RandR (Resize, Rotate and Reflect Extension) protocol to X Server 1.13; this protocol is used by the GNOME and KDE display configuration managers and by the xrandr command line program. However, to use hybrid graphics technologies via X Server 1.13 and RandR 1.5, the rest of the graphics stack components must also support hot-pluggable graphics hardware. These components include the X Server's graphics drivers, and libdrm and its drivers, as well as graphics drivers and the DMA subsystem in the kernel, which has been included since Linux 3.5. The extensions for these components have collectively been in development as "PRIME" and are currently being added to the Linux distributions' development branches. NVIDIA also plans to extend the proprietary Linux driver to support Optimus via the PRIME infrastructure in the medium term.
In X Server 1.13, the X.org developers have also removed the code to support XAA (XFree86 Acceleration Architecture), a 2D acceleration technology that has long only provided limited functionality. Modern graphics drivers offer EXA or UXA instead.
Like the previous 1.x releases of X Server, the current version has a modified ABI. NVIDIA's proprietary driver was adapted to work with the ABI of the "Iced Tea" X Server generation weeks ago. AMD's proprietary Catalyst graphics driver does not yet offer this functionality.
Several important X developers will meet for this year's X.Org Developers Conference (XDC) in Nuremberg later this month. Topics at this conference will likely include the new features for X Server 1.14. There are signs that the Wayland developers will propose the integration of the code for XWayland support; this allows X11 applications to be executed transparently under Wayland.