Pesky Power Thoughts…


Vampire Power Draw

Earlier today I received an email from a friend who asked the following:

Just a quick question for the professional about our family computer at home…What do you suggest people do with a desktop that‘s pretty much on all day? Should we shut down every evening? Are we wasting a lot of electricity on those nights we forget? 

I thought that my reply might be of an interest to some so I am reposting my email here.

Overall, when a computer is “sleeping” it is really drawing very very little power. All devices regardless of whether they are on or not draw some trickle of power when they are plugged in. this is typically referred to as vampire draw. The times that it is really drawing power (and a lot of it) is when the hard drive is spinning and/or the video board is really working. So, in my opinion here are the things to look at:

Go into the Control Panel in windows (regardless of the version you are running) or system options in OS X and look for or search for “Power Options”.

Now look at the settings.

What you want to be sure to check are the following things:

  • When is the “monitor” put to sleep 1 min, 5 min, etc., never?
  • Time it for the least amount of time you can to save energy. If it is set for say 5 min, this just means that when you don’t touch the computer for 5 minutes, it will blank out the monitor (while the monitor still draws power to be able to be ‘woken up’ it is much much less than when it is trying to display an image.

  • When does the hard drive sleep (meaning that it stops spinning).
  • When a hard drive spins, it is able to access new needed data quickly, but this again draws a lot of power. If it is spinning for 30 minutes or more after the last time you touch the computer this is just wasting energy. If it is set to “never”, it will always be spinning regardless of whether it is trying to draw data or not. Big power waster. Now say you set it to 5 minutes, and you are working on a document typing away happily for 20 minutes… after you hit 5 minutes, the PC would tell the harddrive, “Hey, I have not needed to get anything new from you, go ahead and take a little nap, but if I call, start spinning up again ok?” then the HD slows and sleeps til its needed… when it is, it’s response will be slower as it needs to get the drive platters (think record player) up to speed before it can begin accessing data from it again, but it is not really that long of a time.

  • When does the system go into sleep or hibernate mode?
  • The option for this is also 1min, 5min, etc, to never… if set to never, it will always stay on drawing full power even if the monitor and harddrive are “sleeping”. “Sleep mode” is a power saving mode where it it taking a light nap… move the mouse and it will take 10-30 seconds to “wake up” and get everything moving again. This draws less power than full power, but more than hibernate… It’s the “Hey I am not going to be working on you for a couple of hours just chill out…”

    Hibernate is a deeper sleep mode where the computer actually takes anything that is in its memory (open programs, etc.) and writes them to a temporary location on the harddrive and goes into a deep sleep. A mouse movement might wake it up, or some pc’s need a keyboard or box button push to “poke it” hard enough to wake it up. When a computer is hibernating the power draw is really low but waking it up may take more like 45 sec – 1 min as it needs to fully power on and then copy all of what it wrote into the temp file on the hard drive back into active memory. While this seems longer and that it might be just as good to fully shut it down, remember it will most likely take 2-4 minutes (or more) to power on a PC from a cold start.

Too much info yet?

When a PC or Mac is sleeping or hibernating it is not using a lot of power, but monitors and speakers (even “sleeping ones” do… So, here is what I do and recommend:

  1. Review your power settings. Make a choice on monitor and harddrive, sleep and hibernate times as low as you are comfortable with… You can always change these. Think of it like a screen saver, set it too low (too short a period of non-use) and when you drift off thinking when writing that email your screen goes black and you get frustrated that it keeps doing that so you increase it… 
  2. If a hibernate time is not set, set one. That is a good energy saver for when you are done for the say night or don’t use it for a couple of days it will draw the least amount of power. (also good for when you just plumb forget about it…)
  3. Get into a good habit of when you walk away from the computer of just turning the monitor off. The PC will still be on and it takes seconds for a monitor to power on.
  4. Only turn your speakers on when you actually plan on using them for something. A few seconds of no sound is easily corrected as opposed to leaving speakers on for weeks when they are note being used.

Lastly, while this does not fall into a power option, screen “savers” are simply power “wasters.” Change any screen saver you have to just a black screen. Screen savers, while pretty or displaying pictures or sentimental stuff are nice, but they are there… well… for the times when you are not actually looking at the screen… if it is black, it is not drawing much power to create color, etc. and then let’s face it, a few minutes later it is going to go to sleep anyway… because well, you are not working on it… Think about it the other way around, when a screen saver is working to display those images, it is keeping the computer awake or waking it up and it is pushing the monitor (the biggest energy hog) to constantly be using full power…

Personally, when I had desktops (we are a laptop / iPad / iPhone only household now) at home, they were never turned off. I think part of it was laziness, but another part was how we used them. However, even though they (all 4 of them) were always on, I tried to stick with the above as best I could.

Part of the reason I never turned them off is because the hardest time a computer has is when it is being powered on. Think about it this way… when does a light bulb typically blow? When turing it on. This is because first it has no power, then it is drawing down full power instantly trying to make things spin, light up, etc… This situation is the same for a computer. first it is off, then it is drawing full power, trying to make the hard drive spin, powering the video board to send a signal to the monitor, powering the network card to get information from the web and more all instantaneously an all at the same time. This is really hard on machinery and equipment. waking from a sleep or hibernate mode is much more gradual on the pc. So, that was always my choice for minimal wear and tear on something that could be hundreds to thousands of dollars to replace versus possibly a couple of dollars a month for the added energy when left on all of the time.

Obviously, the best and least power consumption would be always shutting down the computer and peripherals. Further, it is even better if you have everything plugged into a power strip as well so you could trip the breaker to kill the vampire draw as well. But, when that is not practical, hopefully, the information above will help reduce the energy you are using to go as green as practical.


One thought on “Pesky Power Thoughts…

  1. For me having a display which uses an IPS panel is crucial. I do tons of image enhancing and graphic design, and so creating precise colours is critical. Plus the fact the viewing angles of IPS panels are much better. My brother owns a TN screen and you are not able to even movie your head without the hues changing. Hopefully OLED monitors will come before long. They can even make IPS panels look bad.

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