# determining total voltage usage?

## gnychis

Hey all,

I was wondering if there is any light weight way of determining what amount of total voltage is being used.  You know, the total voltage from the CPU, wireless card, bluetooth, etc...

Thanks!

George

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## bmichaelsen

There is no use in measuring the "voltage". The "wattage" aka the power consumption might be of interest, but i dont think you will find a generic way to measure this with software for all components.

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## davidgurvich

If you put a meter between the outlet and the power supply, removing any internal battery, that would give you a measurement.  If you repeated that a few times you might get a meaningful average.

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## DirtyHairy

Yepp, there is no meaning in the term "total voltage being used". You apply some voltage to an electric device, and the result is the flowing of a current. The product of voltage and current gives you the power consumption per time which is most likely what you are interested in. As davidgurwich already said, you can measure your systems power consumption using a meter which you plug between you outlet and your computer (devices are sold for exactly this purpose).

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## eccerr0r

I think Sharper Image was selling this or somewhere, but this was the first time I saw the Kill-a-watt being sold in a brick and mortar store:

http://www.p3international.com/products/special/P4400/P4400-CE.html

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93519

But yes, voltage is a scalar, it doesn't do any work, but it has a potential of doing work.  Watt (what?) is Power, that's the amount of energy being used.  And except for some really specialized CPUs (such as some Itanium CPUs), most do not really have a way of directly measuring power consumed by the CPU, nevermind the other parts of the system.

For the CPU you could measure heatsink temperature, but that itself does not give an absolute indication of power consumed, only a relative one...

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## psutokth

Sorry to be anal, but after more than one person had to say voltage wasn't what you want (they were right about that) I have to point out the difference between energy and power. This is something that is sometimes wrong on the news and in press releases too. When you measure watts, the flow of power from the outlet to your computer, you are measuring an instantaneous value, something like 40 watts for a laptop. If you operate in that condition for an hour, you multiply 40 watts times one hour to get the amount of energy used: 40 watt-hours. It's both power and time you need to look at to determine (and hopefully reduce) energy consumption, what you pay for on your electric bill. Shutting the computer down when not in use will likely save far more power than any programs like cpu throttling or lcd dimming can. Also measuring your computer's energy use will probably show you how little it uses (especially if it's a laptop and not a gaming rig) compared to other things in the home like the coffee maker, hairdryer, lights, TV, toaster, and refrigerator, but of course time comes into play here too.

If anyone has any questions about lowering their energy bills, I'd be happy to give it a shot; I am an independent consultant in energy efficiency and renewable energy.

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## John R. Graham

The prior post is absolutely correct.  You might even say, a Joule of a post.  Watt's up with my reply?  Coulomb't resist, that's all. 

- John

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## psutokth

Thanks, hahahahahaha

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## timeBandit

 *john_r_graham wrote:*   

> The prior post is absolutely correct.  You might even say, a Joule of a post.  Watt's up with my reply?  Coulomb't resist, that's all.

 

Ohm my, that's the punniest thing I've read Faraday, at least.   :Very Happy: 

(And a big ++ to psutokth's post. The best tool to reduce energy consumption is the Off switch!)

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## John R. Graham

Good thing we're done.  It Hertz when I talk about alternating current!    :Surprised: 

- John

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## timeBandit

Done? Nonsense! In this, I Ampere-less!    :Shocked: 

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## padoor

with all the above the original poster doesnt seem to respond

gnychis  why dont you edit the post to wattage in place voltage

though no post gave you a way to measure power consumed by cpu drives chips .

it is not possible to measure power consumed by individual components from outside

you can measure the total power your computer consumes approximately by measuring the current flowing into the computer with a mutimeter .

terminal voltage X crrent in amperes gives you the watts .

i am sure it is not going to help you anyway.

unless you are trying to calculate your energy bill per month because of computer

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## John R. Graham

 *timeBandit wrote:*   

> Done? Nonsense! In this, I Ampere-less!   

 Holy smokes.    :Shocked: 

- John

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## Akkara

 *Quote:*   

> it is not possible to measure power consumed by individual components from outside

 

True, but it is possible to get a general idea.

I used one of those kill-a-watt meter (they're great, btw) and measured power use at idle; idle with X going (which curiously turned out to be a little less power than in console mode); with 1, and then with 2 cores running a busy-loop; with 1, 2, or all 3 disks spun down; with disk-I/O happening, etc.  All in all an interesting exercise with interesting results.  (I can dig it up and post it if there's any interest)  The main thing I found was, for a system that needs to be on 24/7, try to have it run all off a single hard drive - those dozen watts each can add up!  Oh, and use the power-off mode on the display screensaver rathar than keeping the display lit with a screensaver going.  The display can easily draw 50% of the computer's idle power.

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## padoor

a p4 2.5 GHz mother board with 2 hdd and cd rom cd writer is rated for 400W power requirement at full load.

a 15 " monitor is rated for about 100W for normal operation.

a 300 to 500 watts of power is used '

it does not help anyway to know individual components power consumption. except for designing heatsinks, fan requirements and the like.

amperes is the basix xurrent unit . in our electronics case it is in milliampere range for each component.

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