Common color depth Xinerama requires that all of the physical screens have the same
bit depth. For example, an
8-bit screen cannot be combined with a
16-bit screen.
Hardware rendering In some implementations,
OpenGL direct-rendering only works on one screen. Windows that should show 3D graphics on other screens tend to appear black, a problem most commonly seen with 3D screen savers. The Solaris SPARC OpenGL implementation and ATI and nVidia proprietary Linux drivers support hardware-accelerated rendering of all screens in Xinerama mode.
Static configuration Physical screens cannot be added or removed dynamically, and there is no way to change the resolution of a screen. This is particularly difficult for mobile computer users, who may use an external physical display in addition to the computer's built-in screen, but only at certain locations. It is recommended that RandR or ATI's or nVidia's single GPU method be used in these cases. Xinerama's lack of support for adding or removing screens causes several problems: • Windows may be drawn to a screen that is not connected to the computer. The user is required to drag these windows to the main screen, but is unable to see them. • Video signals sent to disconnected displays use unnecessary power and may reduce battery life. • It becomes difficult to use a device in multiple locations, where available external screens are likely to be configured differently. These problems are related to Xinerama's implementation rather than its design, and can be corrected with further development.
Window manager support 's xinerama support: tiling on three screens simultaneously. Some
window managers and
desktop environments have limited awareness of the separate physical screens in Xinerama, so that the desktop is simply stretched over the physical screens instead of arranged as a single large desktop. The window manager may place a new window on an unexpected screen, which can be confusing and annoying. Xinerama nevertheless offers the advantage that windows can be moved between screens.
Dead space The physical displays do not need to be the same resolution, and the virtual display area is not necessarily rectangular if the component physical displays are not the same size. Some window managers assume a rectangular display area, and enforce this by creating excess "dead space" at the edges of a display. The window manager needs awareness of Xinerama to avoid placing new windows in this dead space. ==See also==