Frequent correspondent EP sent along some real-world data regarding the power supplies in computers.
I’m posting it here in its entirety to stress the importance of “little” energy savings. Many people are focused on really huge, obvious savings, like increasing the US CAFE standards to something that will have an effect (the new ones are a bad joke), but the small changes can add up to a major benefit. Saving 10 or 20 watts on a PC power supply becomes very important when you have [1] many millions of them running, and [2] they’re running for hours every day, and in many cases 24/7. We have a pretty sizable amount of potential savings right there for the picking, as soon as we get serious about pursuing it.
(Speaking as someone who’s done far more than my share of Windows re-installs and upgrades, for myself and friends and consulting clients going all the way back to version 1.0, I wonder how many kWh of electricity could be saved every year if Windows booted in a reasonable amount of time and didn’t give people such a huge incentive to leave computers running around the clock. But I digress.)
Anyway, on to EP’s missive:
90% efficiency should be possible. Part of reaching that would be to stop chasing insanely powerful power supplies. My P4’s and AMD desktops and servers are between 40W and 160W power draw.
First some interesting sites. This one assumes a lot such as a 40W to 60W power draw with estimated savings of only 5W or so. In reality - my tests show 25% savings - even at low power levels like 60W. But these power supplies shine on a server or high end machine sucking back >100W - giving a payback of 2 years or less (asuming $0.10/kWh, computer on 24×7).
http://www.silentpcreview.com/article684-page5.html
The EarthWatts PS seems to have been released around OCT 2007 and I’d not heard of it - and I’ve been asking my suppliers for just such a power supply. Antec server cases I bought just 8 months ago had the older, much less efficient power supplies.
A web site with info about the 80Plus certifcation - this is just a PDF on it which Google found.
http://www.80plus.org/manu/psu/documents/CORSAIR-CMPSU-550VX-550W-Report.pdf
Ok - the numbers as I measured them.
Basically most computer switching power supplies are only about 65% efficient. I’ve seen exceptions - IBM Evo, Compaq micro case which were signif. more efficient (65W for the Evo and Compaq P4’s vs 100W for a P4 with a generic power supply).
The Antec I tested is PS-AN-EA380, $53 Cdn each (compared to about $30 for a run of the mill 300W power supply).
By “regular power supply” I mean older and non Earthwatt Antec, AOpen, SPI, DTK or other generic power supply.
Test case - P3 computer system ------------------------------ Standby Draw In BIOS In Win XP AOpen FSP250 4W 52W 52W Antec Earthwatt 4W 36W 36W Test case - AMD 2.4GHz Athlon 64 system with Cool 'n' Quiet enabled (double the power rating if Cool 'n' Quiet is not enabled and double it, nearly, again if it's not enabled on a dual core CPU) ------------------------------------------------------------------- Standby Draw In BIOS In Win XP AOpen FSP300 7W 84W 59W Antec Earthwatt 5W 64W 43WI’m not impressed by the standby power draw. I was hoping that it would meet the 1W or less spec. But there is an aprox 25% improvement in efficiency of conversion from AC to DC. Part of this issue is, I believe, the actual amount of power drawn by the motherboard when it’s in standby.
For new servers I have - 153W in Linux for Core 2 Duo’s - the power draw would be reduced to 115W. Savings would be about $40/year in electricity alone. Other benefits include less load on the UPS, better uptime with the UPS, less heat generated (basically 25% less since server rooms don’t have monitors).
I’ve emailed to complain to SPI and AOpen about their horrible power supply efficiency. I’d heartily suggest that you all do that too. This is one of the easiest ways to cut costs, deal with heating and beat a path to a slightly greener future. Only Antec provided a phone line to complain to - SPI and AOpen only provided an email forum on their sites.
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May 8th, 2008 at 10:23 pm
A big chunk of watts is wasted by video processors. A high-end video card can draw as much as the rest of the computer.
There have also been inroads to setting up server farms to run on DC power so that the heat generating parts (of the power supply) can be moved outside the building someplace. Once people get used to having DC power around, then computers become prime candidates for wind or solar charged batteries.
Conservation first: Ditch Windoze and get a streamlined Linux machine for anyone who does the usual stuff: surfing, emailing, word processing. Linux on a 386 is better than Windoze on Vista.
Bandwidth is power. The more people are convinced they need to see the latest idiot stunt on Yoohootube, the worse we are as a species, anyway. Video could be pretty much filtered completely out of the internet and little would be lost.
Computing standards should be established and fixed for 5 years at a time. Moore and his law can take a hike now, the average user is never waiting for their computer to finish crunching spreadsheets these days.
More laptops, fewer game machines.
It’s all kinda like arguing over the cost of a stick of gum, though. The real energy being thrown away is in airplanes and automobiles. The energy in one gallon of gas, when properly used (split it out, push it through a fuel cell for direct DC power), could power a small laptop computer for nearly a year of checking emails every day. (~35 KWh-with a 100 watt laptop, that’s 350 hours).
May 9th, 2008 at 7:06 am
While I definitely agree with the video card and DC power stuff, I have to disagree on some other points.
I have a long history with Linux (I was the reviews editor for Linux Magazine, wrote for several web sites, etc.), and most casual users will not be able to use Linux nearly as easily as you suggest. They typically need a lot of help getting everything set up and configured, and even then they run into a lot of hurdles, like difficulty in dealing with the format of files they download from the ‘net and want to use, etc. I’m no fan of MS or Windows by any stretch, but even with my back ground I don’t use Linux on the desktop–it’s just too much of a pain in the posterior region for daily work.
Filter out ‘net video? Way too draconian, given all the other conservation measures we could exploit first.
I have no idea what you mean by fixing computing standards (hardware? software? both?), and why that means Moore’s Law can take a hike, but it sounds like stifling the market. Doing that a few years ago would have stopped the development of things like the new x86 processors from Intel that just just a few watts of power.
Fewer game machines? Really? You want to outlaw game machines? Good luck with that. (And no, I’m not a gamer, at least not since the original Quake days.)
There’s a fine line between taking tough, decisive action, and forcing one set of limitations and world view on an entire industry. Force electricity generation to be cleaner, promote renewables as vigorously as possible, sure, but don’t strangle one of the industries we need to keep innovating.
May 13th, 2008 at 1:22 pm
I manage a few hundred computers; and I’m forced to run Winblows as our software is all based upon that.
Yes video cards are a bugbear. I’ve seen 20W extra consumption over a motherboard with integrated video. I’ve also seen upper end motherboards (Wifi hardware) which suck 20W more than a micro ATX motherboard which had integrated Gbit ethernet, video, audio.
I keep my stats at http://sca.uwaterloo.ca/~praetzel/personal/Elec-Use-Pollution.html
It’s not the best organized; but that’s where I squirrel everything I measure (short of home energy losses, furnace efficiency …).
Right now I’m just trying to figure out the latest generation of AMD processors. The previous Athlon 64’s were 100W in BIOS and 60W in power saving model (Linux or Windoze). The new Athlon 64’s (LE1620) are 80W in BIOS and 60W in Vindoze - if the power saving is enabled OR NOT! So I’m betting that I’ve got to upgrade a driver to get the CPU to throttle back to 1GHz (from 2.4GHz) to really take advantage of the power saving.
I’ve seen pancake fans (AOpen H340 case) rated at 1.4W; suck 3W on the 120V size and make computers very noise. I can cut power draw and noise by disconnecting them.
As for Moores law - that broke back around 2001. In Dec 2000 I bought 1.2GHz Pentium III computers. The current 2.4GHz AMDs I’m buying are - real world - 2x faster than what I was buying 7.5 years ago! Multiple core CPUs make no difference - even with the digital design software we run that can take a few minutes to run (the mfg says 15% speedup for dual core - but I’ve not seen it).
I only buy AMD single core CPUs. The only Intel’s I’d touch is their mobile CPU in a desktop case - but that’s a lot more expensive than the AMD’s I’m buying and wouldn’t save me anything electricity.
May 13th, 2008 at 1:29 pm
“Green” harddrives.
WD has released GreenPower harddrives:
http://www.wdc.com/en/products/greenpower/index.asp
I would not hold my breath for big savings from them; but it’s a good sign that someone is thinking of this. I’ve always been an advocate of hanging back a generation and buying cheaper / cooler / lower power equipment. Ie I did not adopt SATA harddrives until SATA 2 with NCQ. They represented the first improvement upon PATA harddrives and by the time they came out SMARTMonTools, on Linux, finally supported them properly for predicting harddrive failure.
I expect that these drives would save perhaps 1W in typical use; the quoted 5W savings would be on the cutting edge 1T drives at the highest speeds.
They’re basically lifting the head to reduce drag while spinning and throttling back speed (seek speed) when the drive is being lightly used.
It would be nice if computers could be basic appliances - and just worked. But, the issue is not just Micro$oft, but also software like Adobe Reader; which requires more CPU speed and more RAM with every itteration. Even anti-virus software (Symantec/Norton) is getting unreal. I’ve been uninstallng it on 600MHz P3’s (256M ram running XP) in order to improve system performance. Around here we keep stuff running as long as possible!
Already monitoring are considered electronic waste and I expect that to hit with computers soon. We have to pay $15/monitor to surplus them.