[G4] monitor - turn off or sleep?

[Doug McNutt]

At 12:28 -0500 10/3/08, OBrien wrote:
>> My question is in the interest of energy saving.
>> 
>> What I want to know is would it be better to turn off the monitor 
>> when I'm at work,
>> or at night, while still leaving the computer on, and is it safe to 
>> do this?...........
>
>I leave my Mac running all the time. It sleeps when I'm not using it. AFAIK, when the Mac is asleep all that's on are whatever "pilot" lights are blinking, plus whatever power is needed for the Mac to recognize a "wake-up call" (I don't know if that's significant.) I guess, the only power the monitor is using is for the blinking "pilot" light.

CRT monitors take a lot of energy generating the magnetic field that causes the electron beam to scan horizontally and vertically to create the raster you know as the screen.

For a long time now video cards and chips have had a capability of turning off the horizontal synch signal which controls the magnetic fields. Monitors take note of that and go into a low power mode until the synch signal, 75 kHz or so, comes back.

You can get an idea of just how low your monitor power gets by checking its temperature with your hand near an exhaust area for the air that's cooling it. A good one will generate unnoticeable heat in sleep mode.

But then changing temperatures are bad for circuit boards and you might get more service life by minimizing the number of power cycles. Alternate heating and cooling every 15 minutes should probably be avoided. It's a bit like deciding whether or not to turn off the lights if you expect to be back in the room within a half hour. There's no answer that satisfies everyone.

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