My electricity bills are high and my Dad keeps shouting me for that (I use my computer over 20 hours per day). Below are the few things I am curious to know;

  1. How do I lower my Computer Power Consumption

  2. Is it Vital to have SMPS (Switch Mode Power Supply) with over 500 Watts if you encounter lots of voltage fluctuation

  3. Will Charging My I-pod from a USB port lower the power Consumption compared to charging it directly from the AC unit

  • What are you doing on your computer? Games, word processing, internet searches? – Doltknuckle Aug 30 '10 at 20:20
  • Games , Video editing , Photo Editing, Program Coding , Movies , Music etc . usually i keep 40+ programs always open – subanki Aug 30 '10 at 20:25
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    just to be sure: 40+ processes or programs (as in applications)? cause, that's kinda mindboggling ... – Rook Aug 30 '10 at 22:32
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    I guess turning it off isn't an option... – Ivo Flipse Aug 31 '10 at 8:38

This really depends on your budget... (1 and 3 I will write about - not sure on 2)

The easiest and cheapest thing you can do is to get a 80%+ certified power adapter as these are the best at keeping your bill down and if your machine has a stock/cheap 450w+ PSU, getting a green/high percentage PSU can actually pay for itself in a matter of weeks (depending on usage).

The next thing to do is to see if your motherboard/computer manufacturer offers/supports any power saving drivers... or even switch to a motherboard that again has some sort of green credential - most of Gigabytes new boards are really good at lowering power when it isn't required.

Lastly you could get a laptop! By far they are much cheaper to run.

As for question 3 - This depends on your machine and there is no one answer fits all, if you have an energy saving motherboard, it is possible that it cuts power to the port when it isn't required or it is always active - all I can say for (almost-99%) sure is that it wouldn't take more power than using the charger directly.

I think the best thing you can do is buy yourself an electricty monitor such as a kill-a-watt - they are amazing and you will get addicted to seeing what costs what! (or should I say watt costs watt!) alt text

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    +1 because nothing can beat a real measurement instrument. – AndrejaKo Aug 30 '10 at 18:23
  • @AndrejaKo I bet a lot of money can ;) – BloodPhilia Aug 30 '10 at 18:27
  • @BloodPhilia But without a precise measurement instrument, how are you going to know if you actually do have money and assuming you do have money, is the amount of money small, medium or large. :) – AndrejaKo Aug 30 '10 at 18:51
  • @AndrejaKo A large amount of money could always buy you an ever MORE SO PRECISE instrument :D Beating this one! – BloodPhilia Aug 30 '10 at 18:54
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    Kill-a-watt is the way to go. My iron uses more power in 15 minutes than my PC does all day, so it's very informative in unusual ways. – Garrett Aug 31 '10 at 5:09

You can do a few things:

1.. You can turn off the monitor whenever you leave the workspace (Monitors left on will consume power)

2.. Place the system in a sleep mode, or turn off the system whenever you leave the workspace.

3.. Using the Power Options can reduce consumption (It automatically sets settings for placing the PC in hibernate/sleep. This is a windows Vista and 7 only option. To access it, simply press the start button and type in "power options" and press enter. It will pull up the different options you can select.

Understand that doing all of this will more than likely cause a reduction in speed and performance of the PC.

  • And also, there is a constant power-draw for most devices left plugged in, even if they are completely off - especially laptops. So, unplugging that laptop when it's off will both help preserve it's battery and your electric bill. – rlb.usa Aug 30 '10 at 21:46
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    @rlb.usa: in sleep mode, the disk is switched off and doesn't consume any power, but the motherboard and RAM remain powered. During hibernation, the computer doesn't use any power (except an infinitesimal amount for the clock); you can plug it out and leave it unplugged indefinitely. As far as the hardware is concerned, hibernating is the same thing as off. – Gilles Aug 30 '10 at 22:38

I think that you should first run MS Joulmeter if you can. It is not very accurate, but will give you an idea how much energy your computer uses. This way you can measure how much power various settings will save or not save.

Others wave suggested obvious drastic steps which will make greatest power savings. If you do want to have computer on all the time, here are few things you should consider. First check your BIOS setting for any power-saving options. Look for things like C1/C2 C3/C4 states, Intel SpeedStep (if you are using computer you mentioned few questions ago) and anything that looks power-saving. If you are unsure about any options, look for descriptions in your motherboard's manual or search on the Internet. If you can't find any info, do ask here.

After all power saving options are enabled in BIOS, next step is to check your computer's power policy. To give you a good recommendation, we need to know what you use your computer for. In the meantime, you could try with pre-set power saving mode. If some pre-set option is annoying, change it. Experiment with various advanced settings under power policy and check how it affects Joulmeter readings.

Others have mentioned high efficiency power supply. It is in my opinion a good idea. However if you want to change your power supply, consider obtaining one which can work on a range of voltages. Power supplies which can work on anything between 100V and 250V are not so rare any more. It could help with voltage fluctuations if they are relatively small (read: don't exceed power supply's rated input voltage). On the other hand, such power supplies kill themselves in case of very large voltage fluctuations (one time my power company made a mistake and switched the neutral wire with a phase wire and all "advanced" power supplies died even if devices themselves were off).


1- Power Conservation

General Energy Conservation (like, turning off the monitor instead of using Screen Saver)

You can follow general suggestions like turning your computer off when you're not using it (Here's some more that I didn't even know).

Energy Efficient OS

Energy conservation has recently become a big topic in OS, and you can also consider switching your OS to a more energy conservative one (a little extreme, but perhaps worth it). What the OS does is automatically switch off hard disks and pheripherals when you're not using them, switch your network cards to powersaving modes, and all kinds of other nifty things on the hardware levels. Here, check out LinuxPowerTOP.

2 - Fluctuating Voltage

I don't know = /

3 - iPod Charging

It doesn't make a difference. Your iPod charges for maybe 20 minutes a day and your computer is on for 20 hours? Comparing your iPod charging to your computer's power draw is comparing pennies to dollars, so focus your efforts where it matters (the PC).

4- Wait, 20 Hours a Day?

I think there's definitely some money to be found in cutting away some hours from your computer's 'ON' time.

I suspect that perhaps you are using your computer to do things while you are away from it, for example, torrenting Linux Distros. Consider using a different machine elsewhere to do this (perhaps a university computer), and then transferring the file back to yours. You can also try to bunch your computer tasks into fewer 'ON' hours. For example, instead of waiting till you are asleep to download stuff, consider doing it while you are typing up your homework. Don't kill your productivity trying to save a few minutes, but do look for ways to cut back on whole hours.

5- Wait, 40+ Programs?

I think there's something to be said about this as well. While loading up a program costs some energy for the disk and ram to find it, read it, load it in memory, and start it up, I think there's some energy going to waste with keeping that many programs up. I doubt that you are using them all at one time. What it does do, is cost more processing power, ram, fan-cooling, and possibly disk to keep those 40+ programs running, than starting what few for when and how long you need them (in your general case).

But in perspective, turning off your monitor is probably going to save more energy than cutting back on the number of programs at one time. So, this is a smaller thing that you can do if you choose.


1 - I would say the best (obvious) way would be to turn it off when you don't need it. Apart from torrents, or something alike, I cannot see what could be the need to keep it powered on 20 (?) hours a day (if it acts as a server, why not 24h/d?).

Put it in standby while you're not actually using it. It does waste a little power that way, but has considerably faster re-up time than getting it from hibernation.

2 - Well, I can say no but some will sure argue that. What do you mean under "lots" is the question here.

3 - The difference between the two is in my opinion, negligeable.


The biggest power consumer in a typical desktop computer is the graphics card, especially when using any kind of 3D feature. Turning off 3D effects (and more generally any kind of fancy visual effect) can save significant power.

Trying to use less CPU can also save power. You'll get a particularly bad instructions/Watt ratio if you have background tasks that use small amounts of CPU but fire up very often, because an idle CPU will (if configured adequately) go into a reduced-speed mode where it uses less power.

Do not run any kind of so-called “screen saver”: these programs are often designed to show off visual effects and often consume far more power than normal computer use! Configure your screen to simply go black instead. Also, turn off your monitor when you go away for more than a few minutes: monitors use power even in sleep mode.

Laptop components use a lot less power than desktop components. You pay for it because they're more expensive, and often less ergonomic or less powerful.

Power supplies vary quite a bit in efficiency (i.e. the ratio between provided power and consumed power). Unsurprisingly, efficient power supplies tend to cost more (but you gain it back through your electricity bill).

http://www.silentpcreview.com/ has a lot of resources on making your computer more quiet. Since most noise sources are related to cooling, some of the advice there is about using less power. Check out their forum on green computing.


Are you still using a CRT monitor? That takes up significantly more power than a similarly sized LCD. Also, how many drives do you have in your system? If you have several small hard drives spinning for storage, you can save quite a bit of power by upgrading to larger drives, and/or spinning disks down when not in use. Is the inside of your computer clean? If its choked with dust, the fans have to pull more power to keep things cool.

As another poster said, buying a Kill-a-watt is really in your best interest, as this will help demonstrate things like "My computer uses... 400 kW/h, but the fridge uses 700."

Charging your iPod differently is not going to have enough of an impact to show on the power bill.

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