Is this power usage correct?

[Billbo]

Yesterday I bought one of those plug-in lcd energy meters to see how much power my system uses. I tested it with things I know the wattage of, like kettles, irons, toasters, and even inductive loads like fluorescent lights and room fans. It seems fairly accurate.

When I connected my comp through it though, I was shocked to see it's only using about 68-70W at idle with C1E and EIST enabled. Upon running Orthos blend test it rises to around 80W. Even as the comp is booting with the hard drive working the power usage is shown around 70W.

Can this be correct? I mean the cpu is rated at 65W by itself. The motherboard heatsinks get fairly hot so it's using a few watts as well. Even the case fans use a few watts. And the PSU I think has a rated efficiency of 80% or so depending on load. Which would make the above figures even more unbelievable to me. This meter also displays the power factor which is shown as 100% while connected to the comp.

I will test it again today while running a full system stress test and see what figure comes up. But I just can't see how the above figures are right? Anyone else tested their systems and get lower figures than they expected?

System:

E2160 @ 2.7Ghz
GA-P35-DS3L
Geforce 8400 GS
250GB Seagate SATA HD
2x1GB Apacer 800MHz DDR2
1x12cm rear fan, 1x8cm front fan
Cooler Master 460W PSU

 

[Zap]

Yeah, sounds about right. Enthusiasts usually grossly overestimate their true power requirements, while power supply manufacturers (especially cheaper ones) grossly overestimate the output of their products.

Note that sometimes an APFC PSU will show up as power used, not from the wall.

 

[DSF]

With a relatively low-power CPU and without a high-end graphics card, that doesn't surprise me too much.

 

[Billbo]

But it still sounds too low even for my low end components. I know the 65W rating of the E2160 is Thermal Design Power, not actual electrical power usage. Yet it still doesn't add up for me. Though if that is correct, then I ain't going to complain

 

[Zap]

Intel gives the same 65W rating for all their Core 2 based desktop chips, even the ones with 4MB cache at 3GHz. Figure probably around 40-50W for your CPU running Orthos, and the rest of the parts are nickel/dime for power draw.

If you really feel the need to see higher power draw then you'll need a more powerful GPU and run some 3D program, as those draw more power than the most powerful CPUs.