TITLE
    Apple Displays: DPMS Mode Support
Article ID:
Created:
Modified: 		58288
2/25/99
5/4/00
TOPIC

    This article details the Display Power Management Signaling (DPMS) standard and how it is implemented with Apple displays.

DISCUSSION

    DPMS (Display Power Management Signaling) is a standard developed to save energy and maximize the useful life of computer displays. By switching the horizontal and vertical sync lines on or off, a DPMS compliant video card provides the capability to place the monitor into one of four modes (Normal, Standby, Suspend, Off).

    Each mode puts the display into a different powered state from fully powered up, to the Off mode. In the Off mode, only a small auxilliary circuit is running which monitors the horizontal and vertical signals to wake up the monitor.

    Mode
    H/V Sync
    Power Consumption*
    LED
    Notes
    Normal (On)
    On/On
    Less than 150 watts
    Green
    		Display operating
    Standby
    Off/On
    Less than 15 watts
    Amber
    		Guns off, power supply on
    Suspend
    On/Off
    Less than 15 watts
    Amber
    		Guns off, power supply off
    Off
    Off/Off
    Less than 5 watts
    Amber
    		All off except aux circuit

    Standby is the mode typically set by screen savers when they blank the screen rather than displaying a pattern. The tube filaments are left on to allow a faster recovery when the display is needed again. The Off mode (Energy saver mode) is set when the Macintosh is put in the sleep mode or by using the Energy Saver control panel to put the display to sleep. In this mode the horizontal and vertical sync signals from the Macintosh video output are turned off as well as the tube filaments in the CRT. Waking up from this mode takes a few seconds longer because the tube filaments must warm up.

    Note : The power consumption values provided above are valid only for the Apple Studio Display 17. The actual values may vary depending on which display is being used, and whether DPMS support is enabled.


Document Information
Product Area: Monitors-Displays
Category: General Topics
Sub Category: General Topics

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