The Power Consumption of Modern PCs

janp writes "The power consumption of modern PCs has skyrocketed the past few years. Hardware.Info has done some fairly extensive research on the power usage of various configurations. It turns out the a high-end gaming rig can easily use more than 400 W, and that putting a system in stand-by isn't as saving as you might think. The article has some interesting tips to save on power costs."

I just did some research on this actually

[casualsax3]

A few weeks ago I tested some power supplies to see if it's worth spending $70 on a power supply vs the crappy stock PSU that comes with a lot of cases you can find on NewEgg.

I used Kill-a-Watt power tester, which can test for a number of things - I used raw amps.

I tested 4 machines with 5 power supplies in 0, 1, 2, 3, and 4 drive configurations. I also took a reading of how much power the systems drew when I powered them on at 4 drives, which shows how efficient the power supplies become under serious load (it takes a good chunk of power to spin up 4 drives)

The machines were all tested with the same 1x1GB PC5300 RAM, and the same four Western Digital SATA drives. The Intel systems were LGA775 chips on an Asus, and the AMD's were AM2 - also using an Asus motherboard.

Here are the results (hosted by Voxel.net, so it should hold :) http://newyorkhatesyou.com/Power_Supplies.pdf [newyorkhatesyou.com]

Power supplies tested: http://www.newegg.com/product/product.asp?item=N82 E16817256001 [newegg.com]

http://www.newegg.com/product/product.asp?item=N82 E16817371006 [newegg.com]

http://www.newegg.com/product/product.asp?item=N82 E16817151022 [newegg.com]

http://www.newegg.com/product/product.asp?item=N82 E16817234002 [newegg.com]

In a lot of cases the stock power supply uses almost twice as much power.

In Brooklyn I pay $.19c/kwh, so 1 amp of power can cost around $20 a month - ((volts * amps) / 1000 ) * time (in hours). This means pretty plainly, that the stock PSU here would cost me another $15 per month on my one desktop that I always have on.

Now if an office switches all of our workstations to one of the three 80% efficient power supplies, we stand to save a few hundred per month. Add to that the fact that these power supplies generally have more stable rails, and they should last longer - and its really a no brainer.

No your math is wrong

[Darkfred]

Your 2 pcs at 500w are averaging between 4 and 6c an hour. At full load without power saving, and turned on 24:7 the worst case scenario is $30-$40 a month. In a real world situation this would probably average around $15 dollars a month.
An actually meter on my computer (150 watt power supply, with power saving features) showed that I was averaging around $8 a month.

On the other hand, your "energy saving" refridgerator will cost many times this amount. Mine averages around $70 a month worth of electricity.

You should pick up a meter from home depot, you plug it between the computer and the wall it has a small window with a dial ticking off the KWh.

Re:No Kidding

[alexhs]

They're as 'off' as an ATX can be 'off' with the power supply switch to 'I'. You need a cold boot, but of course you still use some power. It's G2 state [wikipedia.org]

Re:No Kidding

[ashitaka]

No, they can actually be fully "shut down".

On a modern PC with a built-in motherboard you will notice at least one lit LED on the motherboard as long as the PC is plugged in. A tiny amount of power is being provided to the network adapter to listen for "magic packets" which, after being verified, will cause the machine to power up as if you pressed the power switch. This could be from standby or suspend but a cold boot is also possible.

Actually, My iMac is pretty good...

[frostilicus2]

My 1.83Ghz Core Duo iMac has a very low power consumption. See here [anandtech.com]. 64w under heavy load and 48w idle. If I put it in sleep I'd expect [dssw.co.uk] that it uses of the order of 5w. Which is impressive given that this is almost half of the power consumption of the most efficient system on test here.

Re:I just did some research on this actually

[Anonymous Coward]

If you want to calculate how much you're paying you should look at watts measured by your power meter and not amps. The simple watts=amps*voltage doesn't work for inductive systems like computers or most any other appliance. That said, these are interesting numbers, thanks for sharing.