anyone actually measure comp wattage with a power meter?

[draggoon01]

for long while still i see people debate power usage of their computer. especially with respect to what size psu they need for their comp. so i was wondering if anyone actually has a power meter or similar means of actually measuring the wattage of their comp and could post the results.

what would be especially helpful is if the person would include total sytem specs, and power draw during (1) idle and (2) gaming/video-encoding/something-cpu-intensive.

(although of course if someone reports xyz watts max draw, that doesn't mean you only need xyz power supply exactly)

 

[Davegod]

you might be interested in a letter i read on Dans Data recently (old letter tho), look for it i think it as in the letters section http://www.dansdata.com/

all theoretical tho.

 

[Lonyo]

There was a UK PC magazine that at least used to do that. They did under "normal" conditions I think (not quite sure what that means), and during standby. The readings were something like 80w for most when idle, and 250w for most at other times.

 

[draggoon01]

Originally posted by: Lonyo
There was a UK PC magazine that at least used to do that. They did under "normal" conditions I think (not quite sure what that means), and during standby. The readings were something like 80w for most when idle, and 250w for most at other times.

do you remember what the system specs were?



no one has a power meter and, or already, has measured their system in all of anandtech?

 

[bozo1]

For your experiement, you need to know the power draw on the different voltage rails - 3.3V, 5V, 12V - not what the total draw of the entire system is. A powersupply is useless if it can't provide the amount of current needed on any of the 3 rails regardless of the overall total wattage rating or actual total power draw.

 

[draggoon01]

Originally posted by: bozo1
For your experiement, you need to know the power draw on the different voltage rails - 3.3V, 5V, 12V - not what the total draw of the entire system is. A powersupply is useless if it can't provide the amount of current needed on any of the 3 rails regardless of the overall total wattage rating or actual total power draw.

if i wasn't clear, then excuse me. i was actually just wondering the total power draw of modern systems under idle and stress.

 

[bozo1]

Ahh. I did it many years ago and don't even remember the results, even though they wouldn't compare to todays systems. You have to use either a clamp-on ammeter that reads the current though the power cable or connect one inline with the cable.

 

[RalfHutter]

Wouldn't this do exactly what you're looking for?

 

[bozo1]

yup

 

[Lord Evermore]

Jerboy did it once. His PC came up to 90W but I'm not sure if it was idle or not. Not a 2GHz machine or anything, but not a Pentium 100 either.

 

[0roo0roo]

yup, surprising no techie has measured this. would be nice to know. esp for these high clocked athlon/p4's

 

[Lord Evermore]

Not all techies are electrical engineers; obviously most of the "techies" that are hardware enthusiasts actually think you need a 400W PSU to handle a minimally loaded PC. For those that would like to test it, not many want to pay 40 bucks for a device that they'll only use once. It's easier to just read the specifications of the devices to see what their loads add up to.

 

[Mark R]

I've done it, using devices that most of you will have at home: an energy meter (kindly installed by the electricity company) and a stopwatch.

For my 1 GHz Thunderbird Athlon system (256 MB RAM, Geforce 2 GTS, 2x HDD, CD-RW, DVD-ROM, SB Live) - power consumption is about 90 W at idle (empty windows desktop) - rising to 125 W when at max CPU load (e.g. Quake 3). 17" monitor was an additional 85 W.

A low-end Celeron system (Celeron 766, 256 MB RAM, i810 integrated stuff, HD, DVD-ROM), consumption was 50 W idle, 55-60 W full CPU load.

Don't forget that most PC PSUs have an efficiency of about 70%. So, in the first example, at full CPU load, the Mobo/CPU and drives were drawing about 90 W from the PSU.

 

[glugglug]

Most decent UPSes have a port to connect to the computer to monitor power usage, # of spikes on the line, input voltage variance etc. Usually through a 9-pin serial port. You can then generate nice graphs of your computer's power usage.

 

[RalfHutter]

This would let you do what you're talking about for $5: DIY $5 Power Meter from SilentPCReview.com.