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.