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Active
01-03-2010, 06:41 PM
Dick Smiths have an Elto mains power meter for $25.
http://www.dse.co.nz/dse.shop/4b8b4f500132c976273fc0a87f3b06bc/Product/View/M7319
Anyone know if this will accurately report PC power consumption? I'm running Folding at Home clients (SMP and GPU2) and want to know how much it's going to cost me to run 24/7. :punk

DeSade
01-03-2010, 06:45 PM
All I can tell you is Elto powerboards are utter rubbish.

Speedy Gonzales
01-03-2010, 07:50 PM
I wouldnt bother with FAH either. It can slow a system down. Theres some reviews there. Click on reviews. It not that good

Agent_24
02-03-2010, 09:03 AM
Of course it's going to slow the system down, it will be trying to use maximum CPU time... (which is the point of it)

Chilling_Silence
02-03-2010, 10:50 AM
From the Specifications tab on the DSE product page:


Measures an appliances power usage
Displays Voltage
Displays Current
Displays Power & Power Used
Displays Cost

Sounds like what you want, yes? :D

Active
02-03-2010, 05:42 PM
F@H only uses idle cycles at lowest priority so scales back when any load is detected. In my observations I have not seen any slow down on the cpu side and only minor slowing on the gpu. Either client can be turned off at any time anyway, so if you're going to do something intensive you just switch it off.

I find the science behind it intriguing. The fact that the combined processing power is over 4x that of the world's fastest supercomputer (Cray XT5) is also quite remarkable, with power consumption being more or less on the same scale, I believe.

The Elto might be the best available at that price, will see if I can find any alternatives.

Speedy Gonzales
02-03-2010, 05:58 PM
Of course it's going to slow the system down, it will be trying to use maximum CPU time... (which is the point of it)

Yer I know what the point of it is. IMO its a waste of space and time

trinsic
02-03-2010, 06:03 PM
Looks like it would work (why wouldn't it!).

One of the reviews states they used it on a laptop. Also it can measure usage over the month and tell you how much it costs :D

(always wanted one)

Chilling_Silence
02-03-2010, 09:00 PM
Pretty cheap too, tempted to get one (or three) for here :D

Terry Porritt
02-03-2010, 09:30 PM
Despite a wide ranging search, I couldn't find out about the accuracy of this device, and it was asked ..."if this will accurately report PC power consumption?"
The so-called "specifications" on the DSE site are next to useless, no accuracy, resolution or ranges quoted.

Neither could I find specifically whether it measured power factor, though there were suggestions that it did.

There were reports that it wasn't all that good for measuring "low powers", but not much indication of what was meant by "low", but I take it to mean power level commensurate with the last digit readout, whatever that is, 1 watt or more.

Since it has a NZ plug and socket, it will be rated at 10 amps at least, I read 16 amps for a similar meter having NZ plug adapters, so it would probably have to read up to at least 230v x 10 amps = 2300 watts.

If it is a 3 digit display, the smallest power reading may be 10 watts, which is a bit high.

This is all guesswork :clap

Better to read the accompanying leaflet before buying.

rumpty
02-03-2010, 10:21 PM
One wonders how accurate these cheap meters are when it comes to measuring the current waveform of a switch mode power supply. True RMS?

Agent_24
02-03-2010, 10:44 PM
Neither could I find specifically whether it measured power factor, though there were suggestions that it did.

I thought power factor didn't matter in a residential scenario? (if you are talking about the electricity bill)

Terry Porritt
03-03-2010, 07:52 AM
I thought power factor didn't matter in a residential scenario? (if you are talking about the electricity bill)

Well, households have quite a few motors running all the time, fridges, air conditioners, heat pumps etc, so it would be an advantage to know the power factors.

Agent_24
03-03-2010, 10:06 AM
Why is it an advantage though? For the purposes of this meter - finding the cost of running a PC - I would have thought power factor wouldn't matter.

As far as I know, only industrial customers are charged on power factor. Or have I got it wrong?

I admit I do not know much about this, having only picked up what I know from reading websites about "Power factor correction" circuitry in PSUs and why it (apparently) is just a marketing point and serves no real useful purpose in the context of home use...

Terry Porritt
03-03-2010, 10:47 AM
Why is it an advantage though? For the purposes of this meter - finding the cost of running a PC - I would have thought power factor wouldn't matter.

As far as I know, only industrial customers are charged on power factor. Or have I got it wrong?

I admit I do not know much about this, having only picked up what I know from reading websites about "Power factor correction" circuitry in PSUs and why it (apparently) is just a marketing point and serves no real useful purpose in the context of home use...

I meant advantageous in the sense it would be interesting to know the power factor for different appliances, not that there is anything that can be done about it :)
On the practical side, if the meter does not measure power factor, as I believe some such meters do not, then the power readings and the cost calculations will be in error by around 2 percent or so.

This may be less than the accuracy of the meter, so may not be worth worrying about unless there is a device with a very poor power factor.

So I agree with you.

Active
03-03-2010, 05:52 PM
Thanks Terry and others for your advice and contributions to this thread.:clap