Graphics Administration Guide (July 2008)

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extensions
double buffer extension (DBE)
DBE is an extension to the X Server that provides a double-buffering API. For more
information about DBE and the API, consult the DBE man pages:
DBE
XdbeQueryExtension
XdbeGetVisualInfo
XdbeFreeVisualInfo
XdbeScreenVisualInfo
XdbeAllocateBackBufferName
XdbeDeallocateBackBufferName
XdbeSwapBuffers
XdbeBeginIdiom
XdbeEndIdiom
XdbeGetBackBufferAttributes
display power management signaling (DPMS)
Monitors constitute a large percentage of the power used by a workstation even when
not actively in use (i.e. during screen blanking). In order to reduce the power
consumption, the Video Electronic Standards Association (VESA) has defined a Display
Power Management Signaling (DPMS) standard which can be used to greatly reduce
the amount of power being used by a monitor during screen blanking.
The following table is a description of the states that are defined by VESA. The Power
Savings column indicates (roughly) the level of power savings achieved in the given
state. The Recovery Time is the amount of time that the screen takes to return from a
power saving state to an ON state (by pressing a key or the moving the mouse).
Table 2-4 DPMS Levels
Recovery TimePower SavingsStateLevel
NoneNoneOn0
ShortMinimalStandby1
LongerSubstantialSuspend2
System DependentMaximumOff3
26 configuring X Server on HP-UX (OEM graphics cards)