Reducing the Power Consumption of Overclocked PCs

babyshiori writes "Now, that must sound pretty inane. After all, overclockers employ all kinds of power-guzzling methods to improve their CPUs' overclockability. However, there are many good reasons to do so. In this guide, we will not just look at theoretical tips on reducing power consumption in overclocked PCs, we will also look at how well they work in real-life situations. Best of all, we are shown why they will improve our PCs' power efficiency without any real loss in performance. Start doing your part in saving the planet now!"

Not saving the planet

[by Anonymous Coward]

Energy conservation isn't about saving the planet - the planet doesn't care. It's about saving humans. We'll all die out and the planet will quite happily go on without us.

Re:

[value_added (719364)]

Energy conservation isn't about saving the planet - the planet doesn't care. It's about saving humans. We'll all die out and the planet will quite happily go on without us.

Actually, that's a common enough mistake for most people as to be forgivable. In the West, we have this notion that we're born "into this world" with an implicit assumption we're separate from (and possibly, above) it all.

Asking people to view themselves as being "of this world" would allow people to see "the environment" as "our environ

Everyone wants to save megawatts...

[by Anonymous Coward]

It was going well until I got to 'I can save 13 megawatts per month'. Obviously this article was written by someone who has a deep technical understanding of power and energy consumption, and not just some kid who thinks he is a 'l33t haxor' because he found out how to use the utilities that come with the motherboard to turn his overclocking on and off.

Saving the world

[maxume (22995)]

If you are really worried about it and you drive, drive less.

1 gallon of gasoline = 131 megajoules = ~36 kilowatt hours.

Waving hands around about efficiency and so forth, that's 1 kilowatt hour of energy per mile driven. So that's 5-20 hours of computer use (assuming between 50 and 200 watts, 500 watts is still 2 hours) per mile driven. Using a more efficient computer is good, but finding a way to not drive 5 miles a day is a considerable amount better.

(If you aren't worried about it, that's fine, but if you are worried about it, for god's sake, do the easy, effective things before you start telling people about the difficult, pretty much a wash things that you are doing.)

Re:

[CastrTroy (595695)]

Another solution would be to get a cheap lowpower laptop and use that whenever you don't required the full power of your overclocked gaming rig. When you're playing games, if you really thing you need the power, then feel free to use it. Otherwise, if you're just browsing slashdot, a $500 laptop would probably do the job just as well.

Re:

[MilesAttacca (1016569)]

On the other hand, think of all the energy that goes into producing all the new computers out there, from mining and refining the often-hazardous materials, to making chips, assembling circuit boards, packaging, and shipping. I can't do the math, but it might be more environmentally friendly to just stick with one computer that can do everything you could possibly want, than to buy two and alternate.

The best solution I can think of (without completely ridding yourself of computing machines, and going off

Re:Saving the world

[DarkOx (621550)]

The other thing to consider is maybe we should look at increasing the lengh of the hardware life cycle rather then constantly cutting it. We should start demanding that software vendors start producing tight efficent code again so that we don't have to keep replacing our machines to use it. We should demand hardware vendors produce platforms that have a long life span with an upgrade path that enables most components to be resused as much and as long as possible.

These is all speaking of primary systems.

I had my first PC, and 386DX-20 for almost 10 years(MSDOS and later Windows 3.x added).
My second system a Gateway P5-90 for about 5 years(MSDOS and Windows 3.x).
My third system home built Cirix 8686-233 for about 3 years(Windows 95 and later 98)
My fourth system home built K6-2-450 for about 2 years(Windows 2000, later Slackware 8 after ---------frustration with the performance of win2k)(would have kept it longer but it broke)
My fifth system now about 8 years old Athlon-800 (Slackware 10.2 and now 12.0 I am even using compmgr on X and enjoying sexy transparent windows!) (works fine with my lowly geforce2-mx400)

Scary trend in that propriety software world. Other then playing and encoding some video MPEG2 and 4 are fine some of the more recents ones are pretty slow to encode and difficulte to play back properly; I can do just about everthing as well with my 8 year old box as can be done with a brand new one. I chose software that is not wasteful and can thefore get allot of miles out of a machine now. I grant you I am not a PC gamer, I have a Wii for that. I am pretty confident the enviornmental impact of my having replaced this machine at least once if not more then once in the Commercial software world would have been greater then any questionable power efficencies of this older equipment, CRT included. The power draw of PCs has not exactly been trending down in general so its likely new gear would save little there at all if anthing the main offset being an LCD rather then the CRT.

Re:

[hairyfeet (841228)]

Or you could do as I did and pick up an older PC that was probably going to end up in the dump for little to no cost and use that when you aren't gaming/compiling. I am typing this on a circa 2000 HP Pavilion mini-tower with a 1.1Ghz Celeron that i picked up for a song because the bad case design caused the little CPU to overheat due to lack of airflow. After pulling one of my bosses "white trash specials" and taking the side off and cooling it with a box fan(which also circulates the room air and helps me

Re:

[toddestan (632714)]

The best solution I can think of (without completely ridding yourself of computing machines, and going off to milk some cows) is to satisfy yourself with a single, old laptop that you bought used. But who on Slashdot would do that? I know I couldn't.

If you just want another computer to use to browse the web, an even better solution would be to dumpster dive an old P3 system, or something like that. I've gotten pretty high end P3's from the trash (1Ghz, 512MB, 40GB) which would be more than enough to browse

Re:

[by Anonymous Coward]

$500 buys you a lot of kWh. Buying a second computer will likely cost you more money than you'll save. From a "green" point of view, you have to compare the environmental impact of the extra kWh you're consuming vs the environmental impact of producing a laptop. Again, most likely the extra kWh are a better choice.

Re:

[dreamchaser (49529)]

I prefer to eat a lot of meat, go on lots of joyrides, and burning a lot of brushwood from our semi-wooded yard. You see, we were going to move to North Carolina from Pittsburgh, but I figure it will be a lot less cheaper for me to just create as much volume of greenhouse gasses that I can so that global warming will just move the NC climate up this way.

Re:

[jadin (65295)]

My problem with comments like yours is that there's nowhere saying you can't do both. Just because you 'help the environment' in one way, doesn't mean it's exclusive.

Well two things

[Sycraft-fu (314770)]

One, it may not be possible to drive less. It's easy to tell someone "Oh just drive less" but what if (as with many people), their daily drive is to work? It isn't as though it is trivial to just find someplace to work closer to where you live, or move closer to your work.

The second is that just because cars are the biggest user of energy, doesn't mean it is worthless to optimise where you can. Lightbulbs are a good example. They really aren't that big a power user over all. Your average incandescent lightb

26megawatts?

[Dr.Diesel (812427)]

He is saving 26megawatts per month? I didn't know Intel made 13.8KV 3-phase E6850s?

Re:

[evanbd (210358)]

We're talking about an overclocked CPU. He upped the voltage, and it draws more current now. What, you thought the cooling tower in the driveway was for show?

Re:

[failedlogic (627314)]

If I could store that energy in 39 months (roughly) I'd have 1.1 gigawatts. My options would be to get a substantially better computer from the future or go in the past and correct this post if my math is off.

Start doing your part in saving the planet now!

[by Anonymous Coward]

I've been hearing a lot of this kind of fluff during earth week.

If you really wanted to save the planet, you wouldn't be overclocking your computer at all or buying a new car because it was hyrid. You would be beating what you have already consumed until it fell apart from overuse.

Most of these "earth saving" techniques seem like nothing more than feel good consumerism. Eco this and green that. Nothing more than words.

And if your computer was burning 24/7 in the development of new energy technologies or new effiencies you would really be saving the planet. And all these real efforts at saving the planet are going to require technology and huge amounts of energy use and chemicals and industry and all that supposedly evil stuff.

 

Re:

[Burz (138833)]

However, the article doesn't have any elements that would entice the reader to buy more stuff. He's not very pointed about it, but is essentially saying that if you need the processing power then moderate overclocking is a pretty 'green' option.

Some people on the CPDN forums track their system efficiency in terms of work units per Watt-hour and have noted the dramatic increase in efficiency in opting for a quad-core CPU even over a dual. TFA's advice has a lesser but similar effect and I would recommend it

Re:

[Spoke (6112)]

If you really wanted to save the planet, you wouldn't be overclocking your computer at all or buying a new car because it was hyrid. You would be beating what you have already consumed until it fell apart from overuse.

Unfortunately, it isn't always better to beat what you have already consumed until it falls apart. Whether or not it's better to beat something into the ground until it is not longer usable or repairable or to buy the latest high efficiency model depends on:

1. The impact of manufacturing said item.
2. How many fewer resources said item consumes during use.

This analysis is called a life cycle analysis.

For example, your typical computer consumes much more energy during manufacture than during use. So for this

Re:

[AK Marc (707885)]

If you really wanted to save the planet, you wouldn't be overclocking your computer at all or buying a new car because it was hyrid. You would be beating what you have already consumed until it fell apart from overuse.

Why? When I buy a car, the one I trade in isn't destroyed. If I don't buy a car, someone else will. The number of cars on the road is growing relatively steadily. So the choice is whether I buy a fuel efficient car, passing along my old car to someone else that will use it until it will

Re:

[dreamchaser (49529)]

I'm pretty sure we have *some* effect, but I'm also pretty sure it's a minor one. Unfortunately, politics has taken over science and everyone is screaming "the sky is falling". Nobody likes to talk about how the IPCC report's abstract, summaries, and conclusions were written entirely by politicians.

It's just a power grab. Hey, we can tax CARBON EMMISSIONS! Great! That's an excellent way to reign in all that evil capitalism.

Mark my words, if the current hysteria persists they'll be talking about taxing us

Next up in the series

[by Anonymous Coward]

Improving the gas efficiency of your Humvee using proper tire inflation.

Ways to cool CPUs

[theurge14 (820596)]

* Set your desktop background to something like penguins or polar bears
* Install a screensaver with air conditioning capability.
* Set your beer on top of the case so the cold will seep down into the computer.
* Type slower as fast typing causes heat friction. Also avoid CAPS and waving the mouse pointer around too much.
* Use a lighter color scheme on the desktop instead of dark as dark colors absorb light and generate heat.

Start with an efficient processor...

[hottoh (540941)]

There is often one in a family. Remember the 1.13Ghz PIII, the AMD x64. Right now it is the 45nm Core2Duo [wolfdale] processors.

Target undervolting 10% and OC the FSB about 10%. Of course turn on the energy saving features like the C1E reported in the story.

this just in: voltage is measured in Hz

[junner518 (1235322)]

FTA

Increasing the voltage by 500 MHz to 3.9 GHz

volts are J/C thank you very much

80 Plus

[Hatta (162192)]

He didn't mention 80 Plus [80plus.org] power supplies. Not only will you save power, your case will be cooler.

what's the mess with cpu overclocking?

[gzipped_tar (1151931)]

Does overclocking indeed improve the performance? Unless you can show that the CPU clock freq. is the true bottleneck of your computing tasks. Often it is not so. Clock rate != performance and vice versa.

For most users the CPU works just fine out of the box. My laptop with a Pentium-M class chip even works underclocked by default to reduce power usage. BTW, it runs Linux of course.

I hope the whole overclocking thing could be stopped if you care about energy consumption.

There's a classical joke that the

Re:

[Belial6 (794905)]

I can tell you that my system is CPU bound a lot. Of course, If I increased the speed of my CPU by 10% by overclocking, it would still be CPU bound, and getting a task done in 54 minutes instead of 60 isn't really worth the effort of overclocking. This is particularly true when it comes to the kinds of things that take an hour to run since I will likely not be sitting and watching my screen count down for an hour anyways.

Re:

[mako1138 (837520)]

It's pretty application dependent. For most desktop usage, more clocks aren't too useful, but for video encoding, gaming, and such, CPU performance is the limiting factor.

I'm running my E2140 (stock 1.6 GHz) at 2.8 GHz. I'd say it's a worthwhile overclock.

Re:

[Awptimus Prime (695459)]

I only ever noticed a speed increase when overclocking video cards back years ago. If your Quake is only getting 20fps in 1024x768, the extra 5fps was kind of key to comfort playing.

Nowadays, it's just stupid. If you are getting 80fps at 1600x1200 with FSAA, you won't notice an extra 10fps. People will swear it makes a difference, but I don't see it.

I'll tell you why overclock features are present: It's because of the kiddy kulture regarding the practice. If you toast your video card, mobo, cpu, etc -- you'

Not so silly

[NMerriam (15122)]

I don't know why people are being so negative about this article. It isn't trying to convince you that overclocking is the most energy efficient thing to do, it's trying to show you ways you can be more energy efficient if you do choose to overclock. People who overlock do so because they want higher PEAK performance, not because they enjoy wasting energy 24/7. When you're not in need of that peak performance, it only makes sense to go ahead and be efficient.

The whole article can be summed up by saying:

1) Be sure to enable whatever idle tech your motherboard/processor supports (speedstep, cool'n'quiet) so that it automatically slows down the CPU and power consumption when not under load.

2) Try undervolting, use stability tests to find the lowest voltage your particular CPU can use, rather than simply using the default.

3) If your motherboard/processor comes with some software that lets you configure the clock speed/voltage on-the-fly, go ahead and test stability under different settings and save those configurations and use them when appropriately. I'd add that most video cards have the same type of software these days -- go ahead and overclock them when you're gaming, and be sure to slow them back down when you're done.

Neither of those should be shockingly new ideas to anyone who's been building computers for years, but anyone new to it should find the article informative in the specifics.

Re:Not so silly

[Zadaz (950521)]

People are so hard on this article because, for the effort it's taken to write it, the author could have gone outside and planted a tree and done much much more for the environment in total than this article ever will.

Re:

[NMerriam (15122)]

Yeah, and it would have been more energy-efficient for Al Gore to tend a compost heap than fly around the world giving lectures, but the question is whether he convinced enough other people to make changes to offset the opportunity cost he missed. If 100 people read the linked article over the next 5 years and change some BIOS settings, that's a lot bigger global payoff than anything the author could have done in the hour it took him to write.

Human societies practice specialization, and someone doing what t

Re:

[Awptimus Prime (695459)]

People who overlock do so because they want higher PEAK performance, not because they enjoy wasting energy 24/7.

Just about everyone I've known who's been around computers their whole life think overclocking is pretty stupid nowadays.

Sure, there was a day when you could run a 25Mhz cpu at 33Mhz and see a big jump in performance, but now you can just a couple of percentage points because the tolerances are much tighter.

Plus, unless you are buying the absolute fastest, super dooper extreeeeeeme edition multi-cored CPU, the cooling system will probably cost more than just plunking down for the faster processor to begin

Re:

[NMerriam (15122)]

Well I'm definitely past the age where overclocking is anything exciting, but it does seem like some of the current Core2 processors are much more overclock-friendly than anything we've seen in years. Getting a 2.0GHz part to run at 3.0GHz is pretty significant for your average college gamer on a budget, and isn't a crazy unusual type of performance gain based on my perusal of Newegg testimonials when building my last system. I got the impression that 20-30% clock speed with standard cooling was practically

Re:

[dreamchaser (49529)]

I think the point many people are making is that if one is concerned about it enough to take these steps for very minute power savings then maybe they should just not overclock at all, or, you know, turn off the computer when you aren't using it.

Re:

[ShakaUVM (157947)]

>>1) Be sure to enable whatever idle tech your motherboard/processor supports (speedstep, cool'n'quiet) so that it automatically slows down the CPU and power consumption when not under load.

Which doesn't work with overclocking on most mobos.

>>2) Try undervolting, use stability tests to find the lowest voltage your particular CPU can use, rather than simply using the default.

Which doesn't work with overclocking on most setups. OCing usually requires you to raise the voltage.

>>3) If your mot

Why pay to cool & heat things in the same hous

[F34nor (321515)]

If the thermal load per square cm of a cpu is as hot a a nuclear reactor why don't we use them as hot water heaters? Cold water to cool the cpu hot water out to wash my filthy ass.

Re:

[Yetihehe (971185)]

Like IBM p575 [crn.com] or heating pools with data centers [ecofriend.org]?

summary...

[by Anonymous Coward]

1) use speed stepping
2) don't overclock as much

wow, great article!

Saving 26 MegaWatt with a PC: solves the global

[viking80 (697716)]

Just in case you read TFA. It states that "When running at full 3.9 GHz, I would save about 26 megawatts a month. Sweet!"
This is incorrect.
26 megawatt is the energy consumption of a medium sized city. Units for saving should in any case be watts, or kilowatthours per month to make it easier to convert to $$$. (note that this is again just watts multiplied by a constant: "kilo" and "hours/month")

Let your fan run faster.

[leuk_he (194174)]

If your fan runs faster, your cpu temperature is lower, resulting in less current leakage.

Quite untrue

[Kupfernigk (1190345)]

The efficiency in instructions per joule of the cpu alone may increase somewhat with underclocking, but the efficiency of the system as a whole may not.

This is because the cpu is not the only energy dissipator in the system and the others exceed it. To take a very simple example: I have a build which takes 30 minutes. During that time, the hard drive is on all the time, so is everything on the motherboard. To be very conservative, assume that at maximum speed the cpu uses 50% of system power.

Now I undercloc

Re:

[Wavicle (181176)]

Now I underclock the processor to, say, 60% of normal speed, and am able to reduce the voltage, and hence the power consumption, by 50%. The system power consumption is now only 75% of what it was. But my build takes around 50% longer. So I use 75% of the power for 150% of the time. The energy consumed in the build is 12% higher with the underclocked cpu.

What was the full speed system doing during the extra 15 minutes the low-speed system was still building? Did it power down so that you can get your 0 watt

Re:

[toddestan (632714)]

If you want to improve the efficiency of a cpu, you UNDERCLOCK it. Not over. seriously, what brain dead dumbass posted this to the front page?

Efficiency is going to be measured in something like GFLOPS/watt. If you can squeeze a 10% performance boost out of an overclocked processor with a 5% increase in power used, you've just increased your efficiency even though you've also increased your total power draw. If you want efficiency, take a low power modern CPU like a Core 2 Solo then undervolt it.

Re:

[CajunArson (465943)]

Already being done. My desktop e8400 (OC'd to 3.6Ghz with a minimum of bother) uses the same speedstep technology that laptop chips have had for a long time. Even though it is overclocked it still throttles down when not in use. Additionally, the cores are throttled individually so if one is being railed, the other can still be clocked lower if it is unused.

Re:

[homer_ca (144738)]

Yeah, my old school E6300 is an overclocking champ too. It's stable at 3.1 GHz and 1.265v Vcore, less than the stock 1.3v. It can fold all day long at that speed, or if it idles with Speedstep enabled it barely uses more power than stock.

Re:

[K. S. Kyosuke (729550)]

Obviously you need to upgrade, as your computer is not fast enough anymore even when overclocked.

Re:

[nigelo (30096)]

Summary:

Save power on your overclocked PC by not overclocking it.

Also, reducing the power consumption of your PC will reduce the power consumption of your PC by JiggaWatts per Fortnight.

Conclusion:
A meaningful way to save power/money is:
Turn off your computer at the power strip, and go out for a conditioning bike-ride, and be ready to bike-commute.
Certainly, do not waste your time using your computer to complain about not being able to read the article.

"Read the article" - what are you thinking?

Re:

[Aranykai (1053846)]

Right, because an intel core 2 duo performs differently when placed in a mac case...

Apple lost that claim when they moved to intel chips.