01-07-2011, 05:00 PM

The idea of my computer going to sleep when i dont use it on its own seems like a worthwhile preference.The screen going dim after a few minutes of non-use seems like overkill unless it is really saving wattage use.Has anyone been able to find out how much watts are saved when screen dims?

01-07-2011, 06:01 PM

Originally Posted by mattg3

The idea of my computer going to sleep when i dont use it on its own seems like a worthwhile preference.The screen going dim after a few minutes of non-use seems like overkill unless it is really saving wattage use.Has anyone been able to find out how much watts are saved when screen dims?

Are you talking when the computer is plugged in or on battery power?

I'm assuming you mean on battery power. That might be a tough number to determine...since the laptop itself draws different amounts of "wattage" depending on what's being done on it...and what the preference settings are.

That's why someone watching a DVD with the display brightness high, volume high, and the DVD drive whizzing away may only get 2-2.5 hours of runtime on a full charge...and someone with bluetooth turned off, airport turned off, brightness very low, keyboard illumination off, hard drive not spinning...and just working on a word processing document may get 6-8 hours on a fully charged battery.

- Nick

01-07-2011, 07:48 PM

Sorry,no Im talking about when imac screen goes dim

01-07-2011, 09:21 PM

I don't know the answer, but my "intuition" (for lack of a better word at the moment) would be the opposite. I can see the effect of not having the screen go dim. I cannot see the effect of the CPU going to sleep.

01-07-2011, 10:22 PM

Originally Posted by mattg3

Sorry,no Im talking about when imac screen goes dim

Hmmm...I'm sort of confused why you would ask this question of a desktop. Typically when someone asks this question, it's in relation to a laptop computer running on battery power (and someone is trying to extend battery runtime).

I can certainly see using less power on a desktop would be a good thing...such as saving on the electricity bill...or being more environmentally conscious (being "green")...I just expected a question like this to involve a laptop.

- Nick

01-08-2011, 11:49 AM

Well as a pc person for years i never saw this option but its a default setting in the imac.Screen goes dim if you are not using it and eventually computer goes to sleep and screen goes black.Just wondered if this setting has much value in saving wattage.

01-08-2011, 11:51 AM

Originally Posted by mattg3

Well as a pc person for years i never saw this option but its a default setting in the imac.Screen goes dim if you are not using it and eventually computer goes to sleep and screen goes black.Just wondered if this setting has much value in saving wattage.

"Sleep" & dimming of the screen brightness certainly save energy. That's basically it's main purpose with Apple laptop computers...to conserve battery runtime when running on the battery. Sleep & dimming of screen brightness on a desktop computer may not have as much benefit...other than reducing a persons electric bill by some very teeny amount.

- Nick

01-08-2011, 12:08 PM

Apple only gives numbers for the iMac's power usage when the screen is on (at no determined brightness value) and when the screen is off, but everything else is running. The difference in power usage is drastic in the most recent iMacs, since both the cpu and gpu throttle down considerably when idle.

So in that regards, it's very hard to tell. (there's probably some oddball program for it on windows)

I wouldn't worry about the power usage when dim, however. It always came to me as more of an annoyance than luxury, so I always have turned it off.