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."

Comments

Conserving energy by not using applications

[Radon360]

I think the author of this article tried conserving energy by not using spell check.

Re:Conserving energy by not using applications

[D4rk Fx]

He wsa jstu tyirng ot rerutn teh lteters to thrie natrual rnamdo staet ot icnresae entrp!oy

Get Laptops or smaller

[Salvance]

If you're worried about power consumption, you're not going to buy a top of the line gaming rig. You'd probably buy a relatively low powered laptop (or even buy a very underpowered laptop similar to a OLPC machine). Gaming machines will continue to be bigger and bigger power hogs. More power consumption = faster and better gameplay, no way around it.

Re:Get Laptops or smaller

[tomstdenis]

Not really. more crap in game IMPLIES more power, but compare say a 486 to a Core 2 Duo. The latter is much more efficient per MIPS than the former.

To put it another way, to match the power [in MIPS] of a typical 1989 486 desktop, you could do so with far less power consumption today. The problem is few companies write conservative software. Go ahead, make your application inefficient, a new cpu is always around the corner!

What people seem to forget is that we were doing word processing, vector graphics and all that on old school Mac IIs in the mid to early 80s. Those programs certainly didn't require hundreds of megabytes of ram or gigabytes of disk space. Of course people associate numerical requirements with quality. CPU has more megahurts? It must be better! Game needs a faster GPU? It must be awesomer! etc...

I'm personally impress with efficiency not bulkyness. Write me a competent word processor that fits on a floppy disk. That'd be a hoot.

Re:Get Laptops or smaller

[Banzai042]

Not always, granted if you want an 8800GTS/X you'll need a big power supply, but if you go with something like the upcoming 8600 Ultra (not the highest end, but should still have some pretty good performance in dx9 games), which has no PCI-e power connector (draws enough power from the slot), just about any C2D cpu, a single optical drive, and a single hard drive, you'll have a machine that's pretty light on power use. Just because it's possible to get a machine that needs a 750 Watt PSU doesn't mean that's your only choice in a desktop, even for gaming. It's all in the components you choose.

modern PCs or gaming PCs? There's a difference

[grommit]

The summary mentions modern PCs but it seems to be about gaming PCs. Posting a story saying that gaming PCs take up a lot of electricity is pretty much stating the obvious.

I'd be more interested to see the power consumption differences between an off she shelf Best Buy computer of 5-10 years ago compared to one of today. Brick and mortar electronics stores are where a good majority of people buy their computers so as far as home computer power usage goes, that's what matters. I'd like to think that with components like sound, networking and video being put on the mainboard and the ability of major manufacturers to set machines to go into a sleep mode by default that computers of today would actually take up less power than those of yesteryear.

Not having any machine of that type around, I can't really do any testing unfortunately.

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

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

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

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

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

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.

Re:I just did some research on this actually

[Spoke]

One other guideline when purchasing a PSU:

Buy the smallest PSU possible!

Many people out there have "SUV syndrome" when buying a PSU and incorrectly assume that they need that huge 500w (or bigger) PSU for their PC. Unless you really do have a high-end gaming PC with a high-end graphics card and multiple hard drives, your computer will almost certainly normally use less than 200w peak, and more typically 75-150w.

What does happen with an oversized PSU is in order to build a PSU to handle high current, it's efficiency at low current drops significantly. Typically the efficiency of a PSU starts dropping pretty quickly below 50% capacity and even faster below 25% capacity.

Finally, you can also look for PSUs which are 80 PLUS certified. These PSUs have been independently tested to be at least 80% efficient at 20%, 50% and 100% loads with a power factor rating of at least 0.9 at those load points.

The Antec EA430 is part of Antec's EarthWatts series of PSUs which are all 80 PLUS certified.

Out of the other PSUs casualsax3 tested, the SilverStone SST-ST50EF is also 80 PLUS certified. I could not verify if the Seasonic S12-380 is 80 PLUS certified, but it does not appear to be so even though it is more efficient than the Silverstone in casualsax3's test. If the S12-380 is of the "S12 Energy Plus" series then it should also be 80% efficient. I wonder if Seasonic quietly started shipping Energy Plus S12s instead of the old ones...

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 your math is wrong (follow up)

[Darkfred]

Obviously I bought a new refridgerator. A 10 year old refridgerator is just not efficient anymore.

But the scariest thing I found during my power audit was that each incandescent lightbulb was taking more power than my computer at rest. A single chandelier in my house accounted for 1/4 of my electrical bill.
By replacing all the lightbulbs with compact flourescent I was able to shave a 3rd off my monthly bill. (still quite high because of an old ac system).

In conclusion your computer is such a minor contribution to electricity that you shouldn't even be considering it before you fix the big offenders.

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

So just don't turn on the heater...

[SeaSolder]

I used to live in a crappy little studio apartment. It was about 550 square feet. The winter I was there, our balmy Seattle weather dropped into the teens for a lengthy period of time, yet I never turned on my heater. The heat being put out by my refrigerator and my Pentium 4 was enough to keep me nice and toasty warm. If you're really concerned about power consumption because of money saving reasons, you could always move somewhere that electricity is cheap. Here I pay about 4 cents per KwH. Nice, huh?

Re:So just don't turn on the heater...

[spun]

Here I pay about 4 cents per KwH. Nice, huh?

So that means you can afford huge sun lamps to combat the pervasive Seasonal Affective Disorder brought on by the constant clouds, eh? I keed, I keed. Seattle's a beautiful place with a lovely climate. All that stuff about rain is just a rumor spread to keep the Californians out. Really, it's sunny all summer long in Seattle. And if summer happens to fall on a weekend, everyone goes on a picnic!

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. 64w under heavy load and 48w idle. If I put it in sleep I'd expect 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:No your math is wrong (follow up)

[HappyEngineer]

Using a kill-a-watt I found out that my computer draws 600W. (3 monitors, dual cpu, high end video card, 4 hard drives, 8 fans)

I was able to reduce my power bill from $250/month to $100/month by turning it off every night.

The upshot is that people should buy a kill-a-watt and find out what the big offenders are. Guessing probably won't work.

What are you guys DOING?

[potat0man]

These power bills make me cringe. $100??? $300!?!?!

My one bedroom apartment with its occasionally used dishwasher, electric stove, fridge/freezer, 4 or 5 LED lightbulbs, 25"tv, router, modem, cell phone charger, electric razor, gaming pc & work pc costs me between $16-$24/month.

This is in Albuquerque, NM. I am pretty efficient. I...

1. Never leave things on when not using them and have everything plugged into power strips conveniently placed on TOP of my desks/tv stand so it's easy to flip off the switch so no standby power is ever wasted. It's just a habit now: Shutdown the pc, flip the power switch.

2. Use LED Bulbs

3. Have gas heat/hot water. Don't need AC. The air naturally circulates in the summer due to a heat chimney, plus my part of the building is shaded.

4. Keep my fridge/freezer packed to the brim with old milk jugs full of water.


I've never NOT done any of these things so I don't know what the bill would be if I didn't. Perhaps I should bite the bullet some month and try it out. But I can't imagine having a $100 electric bill. You guys all have hot tubs and the fanciest christmas displays in the county or what? I don't know if my bill would get that high even if I left everything on 24/7 for the entire month.

Am I an anomally? Is my meter broken? I don't know how I'd even get the bill that high if I wanted to.