Power Consumption

[mugen]

Hello, I was trying to find out what is my wl-500gP power consumption. Also I have a external usb2.0 hard drive connected, do you know the power consumption for one of these also?

I know that a normal hdd on your desktop will consume less than 10W average.

I am trying to know this to decide if I should turn off the hdd or keep it always running. Thanks in advance.

[raas]

Hi,

a bit hard to answer if you don't mention what kind of hard drive you have,

Anyway, the following opinion is my own 2 cents...


If you are using 2,5' external harddrive without an extra power supply a drive would not draw more power than 2,5 watts. (usb spec provides 500mA@5volts, which is 2,5 VA which is 2,5 watts).

If you use a 3,5' external drive with it's external power brick it draws more power.. (eg.. like you said 10 watts)..

Also, please remind, when doing power conversion (AC -> DC) energy is wasted in the conversion process in the form of heat.
A typical power supply (brick/adapter) is only 50% efficient, so in order to produce the power for a device which draws 10 watts, 20 watts of energy is used. 10 watts for the device, 10 watts is disapated through heat.


After this theory one can consider the following..

In my case, before I had this router I had a beefy pc running 24/7 which draws about 150-200watts average. (only for serving my files, webpage and a downloader). Now running my asus (also serving files, webpage, and acts like a downloader) the total setup does not draw more power than 20-25 watts, 6-8 times less than the pc ! to me, that's a real bargain in order to have these 'services running' for you.

If a harddisk consumes 10 watts and it's power supply is about 50% efficient you use about 1 KiloWatt of power every 2 days (not exactly).
(10 watts * 2 (efficiency) = 20 watts)
(20 watts * 24 hours) = 480 watts per day)

I don't know your going rate of your electricity, but let's asume that 1 KW of power costs 10 cents, then you it will cost you about 5 cents a day of electricity.

(pc, 200 watts, 24/7, uses 4.8KW/day which is about 50 cents a day, ten times more!)


What you could do is use a harddrive which automatically spins down, so it will use less power, (but still, some power is used, 'cause it's not 'off' and the power-brick also uses power)

imho.
If you want to cut back on energy costs (which is also a good thing to save the environment) I think one would be better of to search for the 'hidden-energy-waisters' in the house (tv, vcr, mobile phone chargers, old lighting, etc, etc,)


Anyway, I hope my story can help you.

[hugbug]

In my case, before I had this router I had a beefy pc running 24/7 which draws about 150-200watts average.

Have you measured your PC?

I tested mine once (a year or two ago) and it eated about 80W under heavy load and about 45W in idle. P4 2GHz Northwood, 512MB, 2 hard drives. It was much less than I expected.

[mugen]

Thanks for the nice explaination.

The hdd is a lacie 320GB usb2.0 with power supply, so I guess it will do about 20W like you said.

What about the wl-500gP, anyone mesured how much watts it uses?


EDIT: The all idea is also to put all the services on the router and shut down the PC, so I wanted to know how much I will save in watts. The desktop is doing about 220W acording to a calculator I found here.

[raas]

Have you measured your PC?

I tested mine once (a year or two ago) and it eated about 80W under heavy load and about 45W in idle. P4 2GHz Northwood, 512MB, 2 hard drives. It was much less than I expected.

nope not exactly, But I know that setup used a lot of power.
Dual P3 1ghz, 4gb ecc ram, 2 x 72gb scsi 10k rpm harddisk,1x 250gb ide harddisk and lots of fans to keep the harddisks and ram cool. setup was running of a 350w power source, so if I took half of that and added a little to get my figure.

otoh..
I know (all) about power efficient pc's. I have one in my car. 1ghz VIA, 512mb ram, 160gb ide harddisk (3,5) and a 7' vga touchscreen, together with a super-efficient (92+%) switched power supply, it draws less than a head-light of the car.
(power supply is rated at 70w, but can power more than my current setup, and this is which I actually measured... idle 40-45 watts.. load 50-55 watts)


But you've got a point. Pc's tend to be more power efficient than people actually think (thankfully.) still, a super efficient pc can't beat the asus in power consumption.


@mugen,
the bottom of the asus states 'input: 5v @ 2,5a' that's about 12,5 watts netto. max.
I haven't actually measured what it takes under operation.

[luno]

Thanks for the nice explaination.

The hdd is a lacie 320GB usb2.0 with power supply, so I guess it will do about 20W like you said.

What about the wl-500gP, anyone mesured how much watts it uses?


EDIT: The all idea is also to put all the services on the router and shut down the PC, so I wanted to know how much I will save in watts. The desktop is doing about 220W acording to a calculator I found here.

6.7 Watt. Measured with a Voltcraft Energy 3000 powermeter. 6.9 Watt when writing to a USB stick connected to the Asus WL500gP

[mugen]

6.7 Watt. Measured with a Voltcraft Energy 3000 powermeter. 6.9 Watt when writing to a USB stick connected to the Asus WL500gP

Excellent, I have the router with a 1GB pen so that is what I should expect.
Great improvement since having the desktop power on 24/7.