Solved

Measuring power draw from a computer

Posted on 2004-10-06
6
938 Views
Last Modified: 2013-11-15
How could I go about measuring the actual power consumption of a PC after it is built?

For example, if always use a 350w power supply, is that number the maximum it can supply? If my hardware specs are light (few if any PCI cards, integrated motherboard, Celeron 2.0GHz CPU), what am I actually using?

The reason that I am asking is because I want to use a reasonably sized, inexpensive UPS but do not want to create an unsafe condition. I am only trying to protect against brownouts and momentary power outages.
0
Comment
Question by:wmilliga
  • 3
  • 2
6 Comments
 
LVL 69

Expert Comment

by:Callandor
ID: 12240954
Wattage calculator
http://www.jscustompcs.com/power_supply/

The wattage rating of a power supply is the maximum number of watts it can output.  This, however, can take the form a lot of current on some rails and very little on others.  The 12v rail is usually a good indicator of how good the power supply is, because it is difficult to get a lot of output there if the supply is cheap.

You should consider a UPS from ebay, where you can get an APC 1400VA unit for a little over $200 plus shipping.
0
 
LVL 95

Accepted Solution

by:
Lee W, MVP earned 250 total points
ID: 12241214
Callandor - cool link.  

Yes, the wattage on the power supply is the maximum watts it will provide.  I've found that most computers (P3s and P4s) use ~175 watts on average.  If you run SETI@HOME often, then the use will increase.   I wanted a definitive answer to this myself and found a cheap device that gave me answers - http://www.p3international.com/products/special/P4400/P4400-CE.html  You can find them on e-bay (search for "kill-a-watt") for $15-30.  Very handy.  I use it frequently.  I've found that: a P3 1GHz, 512 MB RAM, 3 hard drives, DVD Writer, no monitor, AND a 27" TV, VCR, Cable box, and Stereo ampliflier (on with volume at reasonable levels uses ONLY 250 Watts of power using this device.  I also connected it to a Single outlet that a 700 VA UPS was connected to.  That UPS, with power strips, supported 2 PCs (P4 2.8 & Celeron 2.8), full tower systems, a laser printer in standby mode, Three monitors (one 19" and two 17") as well as a small network switch and a portable phone, 2 PDA chargers, and a small VoIP box from Vonage were using 500 Watts.

0
 
LVL 3

Expert Comment

by:RyanCh
ID: 12518028
Unfortionately I havn't seen this table updated, but there are several ways you can guestimate how much power you're using.
http://www.microsoft.com/nz/presscentre/articles/2001/august-01_consumption.aspx

Here is an interesting article to read:
http://www.firingsquad.com/guides/power_supply/page2.asp

I would definately suggest reading Tom's Hardware guide to power supplies before purchacing one.  
http://www4.tomshardware.com/howto/20021021/index.html
They also have some informative PS comparison material here:
http://www4.tomshardware.com/howto/20030609/index.html
http://www4.tomshardware.com/howto/20040122/index.html

Leew, you should be careful with that estimate, computers now are using MUCH more than that.  The specifications for the Nvidia 6800 was something like 150W on its own!  With the setup that is described here I don't think that you'll have a problem with a 350 W supply as long as your other compoents (video card, HDs, CD drives...etc) aren't absurd power hogs.  As the first tom's hardware guide shows, often the rating of the power supply is not the amout it can in actuality handle.  

UPS's are very good as well to have, their batteries usually last about 10 years before a new one is needed.  
0
Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

 
LVL 95

Expert Comment

by:Lee W, MVP
ID: 12518320
There's nothing wrong with my estimate.  I did not say it was fact and I encouraged the purchase of a device to calculate that.  MOST people do not have $400 video cards, especially people who describe their systems as above.  The faster thiings get, the more power they tend to take, but even the NVidia card is not going to draw 150 Watts of power while being generally idle.  When playing Unreal Tournament at 100 fps, sure, but not when idle.
0
 
LVL 3

Expert Comment

by:RyanCh
ID: 12518401
However one cannot look at their purchacing options based on the idle power draw from their PC.  While it is true that very few people have $400 video cards, the purpose was to show an extreme example.  I have seen several problems when people under-estimate their power consumption (I thought that the device linked was excellent), but it is usually best to err on the safe side.  You are correct on the estimates on the idle load, It is just better to be safe and do your calculations of power under load.  It is like overclocking, one measures the max temperature under load, not while idle.  

0
 
LVL 95

Expert Comment

by:Lee W, MVP
ID: 12518420
Fair enough - but keep in mind what the question was asking.  
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Today companies are subjected to more-and-more data, and it won't stop any time soon.  But there are obvious opportunities for reducing data, particularly data duplicated among companies.
In this article, you will read about the trends across the human resources departments for the upcoming year. Some of them include improving employee experience, adopting new technologies, using HR software to its full extent, and integrating artifi…
This video demonstrates basic masking and how to edit the mask to reveal the desired image.
Viewers will learn how to use the Hootsuite Dashboard.

932 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now