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Hardware

Power Supply Torture Test 245

An anonymous reader writes "With the latest batch of power hungry graphics cards, the PSU in your computer is more important than ever. If you're looking for a new power supply, check out this group test. They've tested 19 PSUs - some good, some bad and some downright explosive!"
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Power Supply Torture Test

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  • 350W Power Supply (Score:5, Insightful)

    by JohnHegarty ( 453016 ) on Tuesday February 08, 2005 @08:36AM (#11605607) Homepage
    If you ask me (and i think you did) the power rating on power supplys useless. I have seen 300W power supplies (good ones) with better power output then cheap 400W.

    Its the same scam the PMPO ratings on speakers.
    • And this is why we read reviews to get the truth behind the figures.

      Or we would do if the site wasn't /.ed!

    • by gweihir ( 88907 ) on Tuesday February 08, 2005 @08:43AM (#11605660)
      Its the same scam the PMPO ratings on speakers.

      Not quite: PMPO is honest. People just don't bother to find out what it means (almost nothing).

      Writinng 400W on a PSU that fails at 380W is a lie.
      • Re:350W Power Supply (Score:5, Interesting)

        by imsabbel ( 611519 ) on Tuesday February 08, 2005 @08:51AM (#11605704)
        its not a lie, at least not more than pmpo.
        I have seen 250W pmpo speakers that ran of a 10W psu...

        You could also argue that the psu has 500W: if you only need 12v, you can get 20 amps, and if you only want 5v, ... , making it able to deliever 500W, just not all at once.

        I would say that this isnt anymore lying than pmpo (both sucks)
        • Re:350W Power Supply (Score:4, Interesting)

          by gl4ss ( 559668 ) on Tuesday February 08, 2005 @08:56AM (#11605738) Homepage Journal
          well.. then again: don't buy shit.

          i'm torturing an enermax 303watter now.. drawing ~25amps from the 12v line and it's holding at 11.94v(no, it's not driving a computer and quite frankly i expected it to break or shut down but it hasn't done so yet).

          if the highet watt rated one feels lighter than the proper psu's cardboard box you'll know it's a hoax.
          • Re:350W Power Supply (Score:4, Interesting)

            by imsabbel ( 611519 ) on Tuesday February 08, 2005 @09:08AM (#11605810)
            Yeah, i dont.
            I wasnt bothered because of the dismissal of the bad psus, but of the defence of PMPO (which really sucks bad).

            I, too have an enermax. I used to hate them because my first enermax was one of those first dual fan ones with a wrongly placed thermal sensor (intants turbine sound), but the new one i really liked.

            Upgraded from a 450W noname to a 365W enermax, because the noname could power 8hds, but the enermax can.
            But there was no lying involved. the 450W one had 330W combined power on 3&5V, and only 14 amps on the 12V rail, the enermax has over 20 on the 12V.
            So just different specs.
        • Re:350W Power Supply (Score:3, Informative)

          by Lisandro ( 799651 )
          Here's a good article explaining PMPO raitings. [westhost.com] It should clear all confusion.
      • So PMPO is 'honest' but meaningless? What good is a specification that has no bearing on the real-world performance of a system? PMPO is so close to being 'a number I pulled out of my ass' that 'scam' isn't too strong a word for it.
      • Writinng 400W on a PSU that fails at 380W is a lie.

        It's not necessarily a lie. For instance, if a power supply has a claimed rating of 500 watts, it may be that they tested its capabilities at 15 degrees Celsius. While that's not a reasonable temperature to expect the inside of a computer case to be, it is still true that the power supply could adequately generate 500 watts at that temperature.

        The issue here is also that people don't bother to figure out what the numbers mean, or don't do any researc
    • Yup, that wattage rating is pretty much for marketing purposes. Instead, add up the wattage delivered by the three "+" volt lines which will give you a better idea of the actual maximum power output available to your components.

      Even then, cheaper PSUs tend to be a little liberal with these figures and many burn up when approaching their advertised maximum load.

      There are other factors such as voltage stability and efficiency that should also be taken into consideration.

      I guess the moral here is that when
    • I'm always a bit concerned about how much electricity these big computers use. I know that, say, 300W is the maximum output, but what's a typical input?

      In terms of being friendly to the environment, I think this machine wins. The power supply says '45W' on it. ;-)
    • by telecsan ( 170227 )
      The single number wattage rating is not enough to classify a power supply. That combined number is the total power that can be supplied by the 3.3V, 5V, and 12V rails. You can never get 400W worth of power off just the 12V rails (and their negative voltage counterparts). This explains your ability to get a better 300W supply than one 'rated' at 400W. It depends on the ratio between the different voltage supplies. That is why this article is utter trash. Their testing methodology only really looked at
      • Yet, at the same time it is still a useful numer (assuming that the power supply can actually output 100% of its rated power).

        I would imagine that the power supply companies actually measure current motherboards to determine how much power is needed on the +5 and +3.3 rails. Nobody would ever sell a power supply rated at 400W, but with 300W on +5/3.3 and 100W on +12. I bet that if you were to compare the specification for a $10 and a $100 supply, that they would be very similar. The only difference woul
  • pling (Score:4, Funny)

    by private Burrito ( 836582 ) on Tuesday February 08, 2005 @08:38AM (#11605618)
    In soviet russia power supply torture tests you
  • by michelcultivo ( 524114 ) on Tuesday February 08, 2005 @08:38AM (#11605623) Homepage Journal
    Maybe the guys at Trusted Reviews [trustedreviews.com] don't use the recommended Power Supply of it has been /.ed
  • Mirrordot link (Score:5, Informative)

    by PornMaster ( 749461 ) on Tuesday February 08, 2005 @08:42AM (#11605653) Homepage
  • Good, I guess... (Score:5, Interesting)

    by Dragoon412 ( 648209 ) on Tuesday February 08, 2005 @08:55AM (#11605731)
    I always stress the importance of getting a good power supply when I give advice for building PCs, but it seems like something people are largely willing to gloss over, and just go for some cheap no-name with high wattage. It's nice to see a review for these, finally...

    But, of the companies on here, I've never even [i]heard[/i] of Tagan, and it seems a bit sketchy that Tagan wins best honors in their review... which was conducted in Tagan's lab.

    Furthermore, why aren't Sparkle or Antec power supplies tested? Along with Enermax, they're widely regarded as some of the best around.
    • Re:Good, I guess... (Score:2, Informative)

      by glazed ( 122100 )
      Antec good? I worked for a shop that sold a lot of white boxes in Antec 630 cases, their power supplies caused us the most headaches. Some just would boot a given system, we got an entire batch of 20 that were DOA. They're awful.
    • by Savage-Rabbit ( 308260 ) on Tuesday February 08, 2005 @09:12AM (#11605837)
      I always stress the importance of getting a good power supply when I give advice for building PCs....

      Personally I'm happy if I can teach users to remember to switch the powersupply from 110 to 220 volts when recieving computers from bought in the USA before plugging them into a 220v power outlet. I still have trouble not laughing out loud every time one of those ebay jockeys shows up with a PC/MAC that has a burned out powersupply. It must be really frustrating to buy a PC/MAC for a shitload of money and then damage or completely ruin it because you forgot to flip one little red switch.
      • Having to have that little switch deal is cheaping out now, IMO.

        I have a six year old Compaq workstation that autoswitches. I have bought their successor models, and they too autoswitch. Not all my electronics are that way but they are gradually moving that way.

        Not that I've bought a computer from overseas.
      • PowerBooks, anyway, are dual-voltage, which I researched before coming to England. I've had no problems with the power.

        Also, though it may seem somewhat pedantic, it's Mac and not MAC, unless you're referring to a MAC (Machine Access Code is the acronym, IIRC) address. I, however, am typing on a Mac.

      • I'm currently looking at moving to a country where the regular voltage runs in the >200V range. One thing I've wondered is if the PSU's are more or less efficient at greater voltage?
      • by Spacejock ( 727523 ) on Tuesday February 08, 2005 @10:41AM (#11606549) Homepage
        Man, I remember an Atari ST enthusiast back in 1987. He owned the only ST shop in town, and he imported about AUD$14,000 worth of gear for demo purposes (big HD, controller cards, etc - this was before Atari Megadrives. My Megadrive cost me around AUD$1750, so that kind of dough wasn't excessive.) He hooked up a DX7 keyboard with midi cables, both monitors (via switchbox), laser printer ... the whole works.

        Then he plugged it in and fired it up.

        Pity the external hard drive transformer was 110v, and Aussie power is 240.

        A year or so later he could laugh about the way the drive heads were fused to the platters when he opened it up for a look. At the time he was somewhat distraught.

        Another less expensive tale - the tech at a computer shop I used to work for ordered in an 80mb hard drive for a customer in the days when 20mb was the standard. (yes - MB. It was a long time ago...) This thing cost around AUD$800 (about US$600 at current prices), and unfortunately the molex socket on the drive was quite flexible and his glasses weren't quite strong enough. So he put the Molex power plug in upside down.

        End result: I found him wreathed in magic blue smoke, explaining to the distributor that a sudden fault had arisen with the new and very expensive hard drive.
      • Any remotely decent PSU should cope fine with being set to 110V and powered on when plugged into 240. It should simply refuse to power on - and at the *very* worst the PSU its self should fail.

        What's a real killer is switching them from 110 to 240 while they're *on*. I've seen this done ("uh ... where's the power switch... <continues fumbling> *BANG*") and it's *loud*. Astonishingly, even with this abuse the only damaged components of the system were the PSU (duh!), motherboard, and video card.

        Remem
    • I was thinking the same thing. I don't trust any source that has the word "trusted" in their name, as that usually means "lying marketing morons" or "cheating, corporation-backed puppets". I think the first option is correct here.
      • by animaal ( 183055 )
        I don't trust any source that has the word "trusted" in their name


        Yes, it shows they're trying too hard to appear honest. A bit like a country namimg itself "Peoples Democratic Republic of ....". It most likely isn't.
    • TTGI is also good (it's what I'm running right now) and not all that expensive... But they weren't in the test either...
    • by ArsonSmith ( 13997 )
      The power supply is one of those strange things that a cheap one wont make your computer any slower, at least most of the time, but when it blows on you it sure sucks. I have a home server that has only been restarted twice in 4 years. both times have been failed power supplies.
    • I was dissapointed that Enermax was punished for its over current protection. Over current protection is good. It shuts the power off instead of burning your computer. The testers should have put more effort into determining why the over current protection was kicking in. It is reasonable that the current ratings of the Enermax are absolute max ratings. If true then the Enermax was acting correctly when the testers attempted to draw 100% full load. The testers also didn't indicate if the power supply shut o
      • CPU's used to run off 3.3v and 5v lines. Now they run on the 12v. Your fans run on 12v. Your hdd run on 12v. Your GPU runs on 12v. Do you know see why 12v is more important now?
        • You state this as fact, but you don't back it up with numbers. Yes current systems draw more power on the 12v rail. But how much more? How much does each component actually require? The number of 12v components is not interesting. It is the current that each draws that matters.

          Too much misinformation is being passed around. All I want to see are solid numbers.
          • Here [bleedinedge.com], check page 3 & 6, shows estimated amounts. What comes down to is that modern systems use more amps on the 12v rail, with many higher end systems using 16-20 amps 12v. Any Power Supply that can handle the load on the 12v rail will have enough headroom on the 5v and 3.3v.
      • Umm. I think that it is reasonable to expect ANYTHING to run at 100%. If a power supply can provide 400W, then it should live up to it. A current limit is reasonable if set at 105% or more, but not at 99%.
    • Furthermore, why aren't Sparkle or Antec power supplies tested?

      Maybe because the test was conducted in Germany? And Tagan [tagan.com] is widely regarded as some of the best around [3dvelocity.com] (example review) in Europe? (Though not so easy to find in the U.S. yet, a few places have them.)

    • The other big thing missing from the review (unless I missed it) was the noise levels of each PSU. For a lot of us, quiet machines are important, and knowing how close to silent a PSU runs is one of the key features besides power output and reliability.
    • Actually, they mentioned in the article that they wanted to test some Antecs, but couldn't get them in time; and they're planning to do another round of tests in another month or two, and include them.

      I didn't see any mention of Sparkle -- maybe you should send the guy a note and ask him to include them.

      Myself I want them to test 1U rackmount power supplies, 'cause the difference between 74% and 79% efficiency on a rack of 16 1U boxes comes out to over 3 amps per rack...

    • It should be pointed out that this review was done in Europe, and the lions share of power supplies tested there were by European manufacturers. That is why you haven't heard of half of the brands in the test.

      I was a little supprised at the results of the Ultra X-Connect. I was considering buying one of those, and have read a number of reviews that basically state the power supply was a decent one, and that the 3.3 and 12 v rails were solid. I wonder if part of the problem was that this was the European
  • by hcdejong ( 561314 ) <hobbes AT xmsnet DOT nl> on Tuesday February 08, 2005 @08:56AM (#11605736)
    noise measurements. A l33t PSU is no good if it sets up a howling gale in my room.
  • by markmcb ( 855750 ) on Tuesday February 08, 2005 @08:56AM (#11605739) Homepage
    In college, I was the guy to go to if you had a computer problem. One night, one of the football players comes knocking on my door, "Hey Mark, my computer's acting weird, can you come look at it?" I agreed and we walked down the hall to his room. Strangely, the machine was off so I reached my hand out and turned it on. I jumped back at the sound of a loud pop and the sight of flames and smoke coming out of the back of the power supply. Immediately, I reached for the cord and pulled the plug.

    "So can you fix it," he asks in all seriousness. I just looked at him in total disbelief and said, "Man, your computer was just on fire. No, I can't fix it."

    He was really good at football though! :-)
    • I used to work for a municipal utility, and one day I got a call from the power plant that one of their machines' monitors was "rainbowy". I get down there to check it out, and sure enough, it has colored ripples all through the screen. I reach to grab the monitor off the CPU, and the monitor is extremely hot! I grab the the CPU, and it literally burns me. The machine was so hot, it was cooking the monitor making colored ripples fly through the screen.

      I unplugged the thing, waited 20 minutes or so for
  • Damn (Score:5, Informative)

    by GigsVT ( 208848 ) on Tuesday February 08, 2005 @08:57AM (#11605744) Journal
    That page is annoying, it keeps jumping up and down while I'm trying to read it, because of that stupid javascript ad.

    It's kinda silly anyway, the article's premise is that they got access to this $20,000 power supply testing equipment... A set of simple $10-$20 high wattage load resistors would have worked just as well.

    A $1000 scope might help if you want to catch a load dump overshoot, startup transient, or ripple, but it looks like they aren't even concerned with such important specs of a power supply, specs that could burn our your system.

    Anyway, some testing is better than no testing, which seems to be the norm for computer power supplies, so I am thankful that someone with access did these tests, but it would have been more useful if they had tested more than simply steady state load.
    • Re:Damn (Score:5, Interesting)

      by Linker3000 ( 626634 ) on Tuesday February 08, 2005 @09:16AM (#11605879) Journal
      I spent some of my electronics engineering apprenticeship in Unit Test where I had to test 5V 300A and 5V 600A power supplies.

      We had a FET-based active load for testing and we had to bolt the PSUs to the load with 1 inch copper braid, put the units in a thick plexiglass/Perspex cage and run them at 110% of rated load for 10 minutes.

      When we got busy, one of the other engineers soldered up a ton of wirewound resistors to act as a load and fitted them into a spare 19" rack with a large red 'emergency stop' button on the top to cut off the power. The whole rig looked like a McGyver special, but it worked and I wasn't too afraid to use it-but when we got VERY busy, I was told to forget about bolting on the braids, just hold them in place, wind up the active load to 110% and keep it there for 20 secs and 'that will do' - I refused, much to the annoyance of the Unit Test manager who couldn't actually force me to do so!

      The guy who made up the resistor load was really mad - it was the era of the BBC micro and he'd lashed up his own floppy drive, but discovered that he couldn't copy one particular game or program because the drive he was using wouldn't step properly to one of the 'hidden tracks' (or something like that), so he bought an official external drive (for some crazy price - it was 1982, after all), did his copying and then hooked up the ground wire of our PSUs to the chassis of the floppy drive and dragged a wire hooked to the +5v line around all the chips' legs - end result was tons of sparks and one very smoky unit which he took back for a full refund. Apparently he complained bitterly to the shop about the way the drive had suddenly 'exploded'.

      This was also the guy that fell over and broke his leg walking across the car park one sunny day - we really couldn't work out how he managed it! He also removed all the light fittings from a temporary work cabin the night before it was due to go back to the hire shop - when the hire company came to pick it up, they refused to take it so our boss called us all together and said it might be a good idea if the light fittings returned 'tonight' - lo, next day they were all back in place.
  • Anyone have a PSU review summary that includes equipment available in the US?
    • Toms Hardware had a review a year ago. I've been happy with the Antec they reviewed. You know what they say, the best power supply is the one you never notice :-)
      Review [tomshardware.com]
    • perhaps because they autosense the voltage level so there's no annoying 115V/220V switch on the back. Newegg carries them. They topped the efficiency tests in the linked review. Way, WAY more efficient than Antec True-series, and slightly more efficient than the Antec Phantom. Definitely my favorite power supply brand.
  • $20000 (Score:4, Funny)

    by digitalchinky ( 650880 ) on Tuesday February 08, 2005 @08:58AM (#11605753)
    Come on, you don't need $20000 test equipment to push a tiny little power supply to the edge of its existance. The first paragraph looks more like a marketing scam.

    A nice old 3 inch nail bent up and jammed into the plugs for a few seconds should sort the good supplies from the bad :-)

  • by Spacejock ( 727523 ) on Tuesday February 08, 2005 @09:14AM (#11605858) Homepage
    Costs a fair bit, weighs more than a house brick and could probably power the rest of the street, but I reckon I need it. When video cards need 1 or 2 molex connectors you know they're sucking up a healthy whack of juice, and I'm running 3 hard drives, 2 DVD burners and about 4 external USB hubs with all kinds of junk plugged in (including 2 external 2.5" drives and 3 external 3.5, although the latter have their own power)

    I did that online test where you put in the hardware and it calculates your PSU requirements. Mine said 'portable nuclear power station', but the 550W Antec was all I could find.

    Anyone know if card manufacturers are planning slower, low-power modes? I like the way the Athlon 64 winds itself back when not under load, but the fan in my 6800GT runs full tilt despite the fact I use 3d features maybe once a fortnight. (Sure, I wish I could use it more, but work before pleasure and all that.)
    • Your system is suspicously close to mine with some notable exceptions... TTGI 550W PSU rather than Antec, ATI AIW Radeon 9800 Pro rather than 6800GT and I 'only' have a Athlon XP 3200+ rather than the A64... Though I'm about to add another HDD to my list to...

      Strangely I did use to run it all on a 350W, but all my power was low for each rail so I decided I needed to change it out... ;)
    • Actually I really like PC Power and Cooling. I was very disappointed to see they weren't covered. They make a great 510W that I'm using in my machine.
    • Here [jscustompcs.com] is one test. I need at least 360w myself, but I have an Antec Truepower 430. I really like how it it auto adjusts the fan speeds according to the heat in the case. Makes for a very quiet case even with 4 80mm fans in addition to what's in the PWS.
    • Yep. Truepower 550W is a good one. Basically on antecs the TruePower line is good stuff, while the SmartPowers are more or less the usual low end junk.

      I'm using Truepower 550W with Athlon64 3500+, 6800GT, 2GB RAM, Adaptec 19160 SCSI controller and *8* hard drives.

      Still works. Same setup blew older Enermax 465W sky high at the addition of 7th drive. Antec took even the 8th and is still going strong.
    • One question. How loud is it? I'm looking for a beefy PSU, but I'd like a silent one, or as close to it as I can get. Thanks.
  • My last desktop had to be built twice. Once with a good motherboard, good ram, good processor and Cheap case, the second time with a much better enclosure.

    If that case and PS is $45, just HOW MUCH money do you think they're devoting to clean power?

    On a more positive note, the new system is dam-near silent as the better case had a large slow moving variable speed fan controlled by the better PS.
  • 12v Rail (Score:2, Informative)

    by Anonymous Coward
    Wattage means almost nothing, the 12v rail is much more important. Looking for the magic number of at least 15amps but 18 is much better.
  • by Goldenhawk ( 242867 ) on Tuesday February 08, 2005 @09:39AM (#11606056) Homepage
    I was having consistent random crashes - the computer would suddenly reboot (all the way to bios, instantly) with no warning. The only clue was it happened most often when I was doing a disk-intensive task (which meant I had several crashes while the system was writing the FAT... BAD news).

    For months I troubleshot all kinds of stuff, to no avail. New mobo, new processor, rearranged hard drives, reinstalled software, new network card, you name it - one step at a time, but no effect. The crashes continued.

    Finally I happened upon some similar accounts of instability and they mentioned power supplies. I thought I was okay with a 300w supply and my Athlon. Nope. As soon as I replaced it, instant stability.

    Some things to note about my experiences:

    I upgraded to the Antec TruePower 430. It's an extremely quiet supply, even quieter than my processor fan, with a temp-controlled variable-speed fan and a second case fan molex connector that also is temp-controlled. It rarely runs above idle, but my case is always cool. That alone was worth the upgrade price.

    I was loading the supply more than I had realized: I run dual graphics cards, two hard drives, and two CD/DVD drives. The crashes were apparently caused by the hard drives - it's apparently well-known (in some circles) that the highest instantaneous current draw in a PC is when the hard drive head starts to seek (lots of current is needed to get rapid motion and get the seek times down). So anytime I was doing a disk-to-disk operation - like a backup or CD burning - I was loading the power supply dangerously close to its limit. One step over the line, and the processor would hiccup. Boom, instant bad FAT table and a week of rebuilding.

    Finally, this wasn't an overnight problem. I brought it on over time by adding things to my PC incrementally... hey, let's add another drive... hey, a spare graphics card... I can keep the case - it's working fine, right?

    So word to the wise: get a GOOD power supply, and get one that's rated well ABOVE your expected average load. Pay attention to those current draw numbers on the hard drives; wattage alone doesn't tell the whole story, and small spikes can kill you.
    • I had a very similar problem, got 3 HDs and a cd burner in my machine as well as new soundcard with a front port powered from the mobo. Basically over time the secondary IDE would intermittently fail to detect the 2 drives on it. I noticed the problem was worse when i had usb gadget plugged in. So splashed out on a better power supply and a powered usb hub and the system is now completely stable.

      Before this experience i really thought the power supply didnt matter but now i would always buy one with a de
    • I think your experience with switching to an Antec power supply is good reason why if you're running a machine with a faster CPU and 1 GB of RAM you want to get at least a power supply of 350 W or higher made by Enermax, Antec or PC Power and Cooling. They're not cheap, but at least you're have the assurance that your machine will last a long time thanks to the power supply offering stable power to all your computer's components.
    • My Antec TruePower 430 had a sagging 5V rail, got down to 4.5V, harddrive firmware would freeze, system would follow in such and such amount of time.

      I was not near the limits of the supply, it just degraded over time for some reason...
  • Be Careful (Score:4, Insightful)

    by serith ( 658009 ) on Tuesday February 08, 2005 @09:40AM (#11606070) Homepage
    To tie a cheap oem 300watt power supply to a whopper of a PC that you just blew a few thousand dollars on is the biggest mistake most people make, and overlook. Dirty unreliable power supplies that feed your PC are like heart attacks waiting to happen. If you're going to invest heavily into building a new computer, do not over look your PSU. If you do a little research (other than compare maximum power to price) regarding Max power @ watt operating temperature, you'll see that most cheap PSU's are rated say 300watts, but for a nice 30 degree Celsius operating temp. Now let's think about that. How many PC's operate that cool? Also, your better built PSU's will typically weigh a lot more, because they're simply better built. Nice and heavy means beefier power supplies, larger capacitors (to give your board that extra oomph it requires when you boot, or when you load it up), and it might even mean you have PFC included--a Power filter controller. These PSU Companies aren't always out to get the consumer by the jugular.
  • Great in principle, bad in implementation? They use cheaply soldered stuff and fail really easily -- it's happened to my friends, too. Comments?
  • I'm using firefox, anyone else doing so notice the page bouncing up and down a few pixels every few seconds?

    I bailed on the first page over that.
  • The article says "With increasing power requirements the amps on the 12V rail have constantly increased, and if this had continued unchecked a PSU failure could potentially result in a fatal accident. With the new design this risk has been greatly reduced and we should see a transition to dual or even quad 12V rails on all high-rated PC power supplies this year."

    What on earth is this supposed to mean? If your power supply fails only half the contents of your computer will fry?

    On a car, an insurance compan
  • by NoseBag ( 243097 ) on Tuesday February 08, 2005 @11:03AM (#11606771)
    First - I spent the better part of 20 years designing military and aerospace switching power supplies and systems. Admittedly these toys were commercial products, but I think I'm qualified to say the following:

    a) purely resistive loads are a poor model for PC load characteristics, as are purely constant-current loads. But the CC load is a tougher test.

    b) transient line and load response (or lack thereof) can preclude operation at the steady-stete levels tested.

    c) I just skimmed the article as it was loading strange, but I didn't note any specific cross-regulation tests. These types of tests may yield poorer performance measurements. They almost always do.

    d) Testing to see if a PS will run at full load is not the same as seeing if it will START under FL. I didn't notice these tests. Likewise Starting at low or hi input is tougher that running at same.

    e) we ps designers had an expression: Power supplies are like assholes - everyone has one and everyone thinks they're an expert. The former is true (some folks have two :) )- the latter is seldom accurate.

    OK - flame away. I'm gonna go eat lunch.
    • Well said. Back in college, emphasis was put on designing power supplies in my EE course (for non EE majors). It gives you some respect for what those designing these things have to deal with. Meanwhile, like you say, the tests performed were very incomplete. You really need to know how they handle transient loads, and the ammount of ripple in the voltage when the supply is reasonably heavily loaded.

      Also there are things like overvoltage and overcurrent protection. These will shut the power supply

  • There are much better power supply reviews available at Silent PC Review [silentpcreview.com]. The SPCR guys are very silent-centric, but also test the efficiency, temperature, and stress test the power supplies as well. They have many more pictures, and even analyze the heat sink and fan configuration. These Trusted Review guys aren't even close.
  • Seriously, I look down the list and in there I see only two names of power supplies I recognise. Where is Antec, PC Power and Cooling, Fotron/Sparkel, or any of the other extremely common and popular powersupplies (ok, maybe PC P&C isn't popular, but they are the reference for many geeks)?

    Also where are noise graphs? That's probably one of the most important features for me when buying a power supply. Wattage is easy to deal with, I just overspec, most self builders do. It's amazing at the tiny power s
    • > Seriously, I look down the list and in there I see only two names of power supplies I recognise. Where is Antec, PC Power and Cooling, Fotron/Sparkel, or any of the other extremely common and popular powersupplies (ok, maybe PC P&C isn't popular, but they are the reference for many geeks)?

      While we're at it - someone else has also pointed out that Enermax supplies shutting down on 100% load is a feature, not a bug.

      If I drive a PSU at 100% for long enough, one of three things are going to happen:

      • I personally would say that a PS should be underspec'd in it's reported wattage. That is to say if it reports it's wattage as 400 watts that should be a level it can sustain full time for it's expected life. Maybe that means the real limit is 450 watts, whatever. The maximum rating ought to be a useful maximum.

        Like with good, profesisonal, poweramps, they'll give you a power rating. That's the RMS power they can output into an 8ohm load (usually, sometimes they spec other loads too) for an extended period
  • Power Supply Ratings (Score:4, Informative)

    by lcsjk ( 143581 ) on Tuesday February 08, 2005 @11:29AM (#11607017)
    The power supply nameplate ratings are not based on output power but input power. This is a requirement by the international product safety agencies. Look on the nameplate and you will find the CE mark, a UL mark, and other symbols related to requirements imposed by various countries around the world.

    The output power rating, which is what you need for operation, is based on a combination of the outputs that can be simultaneously loaded.

    The efficiency of a power supply is also dependent on the load being used. For instance, the main regulation feedback loop probably has the highest efficiency and the other outputs have secondary post-regulators that require more background power to operate.

    Power supplies operate from a 120 volt or 220 volt input AC wall plug/outlet and undergo some severe transients at turn-on and turn-off. Some of the supplies have automatic voltage sensing circuits to operate from either of these inputs automatically. Nearly all power supplies operate from an internal 340 VDC. This voltage has to start from zero and return to zero when unplugged. Most present power supplies have a keep-alive circuit to allow instant on from a standby condition. (The green wire on the output side.) Don't mess with the green wire with yellow stripe that is on the input side. That one is a safety wire for the input protection.

    A WORD of CAUTION: Give your power supply a chance! Design engineers cannot anticipate and design in protection for all conditions and still give you a power supply you can afford. When you turn it off, wait 10 seconds before restarting so that capacitors can discharge and voltages can settle to stable conditions. You may never be able to make a power supply fail if you don't, but you will not be happy if you do. I have designed power supplies, purchased, and tested PC and custom power supplies. I have two bad hard drives from a system I bought from DELL last year. A friend could not tell that the system turned on (too quiet) so he pushed the power on/off too rapidly and too many times. Twenty years ago,my first computer suffered a power supply failure when I turned it off and immediately changed my mind and turned it back on.


  • Power supply tests typically have major shortcomings. They test only a few power supplies, usually the ones that are most heavily advertised, and therefore are the most expensive.

    The power supplies in the review are available in the UK, and are from only 12 manufacturers. Most of them are so shockingly expensive that there would never be a case in which it was sensible to buy them.

    How about a 300 Watt Power supply from a recognized manufacturer for $18.00 [newegg.com] delivered in the U.S.? Need 600 Watts? Use two
  • by Animats ( 122034 ) on Tuesday February 08, 2005 @12:43PM (#11608059) Homepage
    As usual with these PC power supply tests, the supplies that passed the tests from Underwriters Laboratories [ul.com] work fine, and the ones that don't. In this review, there's a clear picture of each power supply label, so it's possible to check the certifications.
    • The HIPER HP3S350 [trustedreviews.com] appears to be the first of the phonies. The label has the UL "recognized component mark" (the reversed-R U symbol), but there's no UL certification number. That's an indication of a phony; all UL marks must be accompanied by a UL certification number, an E followed by digits. Certification numbers can be easily checked with UL here. [ul.com]

      Looking up HIPER in the UL database [ul.com], HIPER has a few products listed, but none of them are computer power supplies. So that's a brand to avoid.

    • Jeantech [trustedreviews.com]'s power supply label also has the UL component logo without a certification number. They're not in the UL database at all. Uh oh.

    • The Seasonic SS 400-FB [trustedreviews.com] power supply has a proper UL marking, and the certification number E104405 [ul.com] is in the UL certification database. There's not an exact match on model; an SS-400FS was certified and this is an SS-400FB. That's sloppy, but this company is clearly trying to comply.

    • SilentMax [trustedreviews.com] has no UL logo at all. It blew up under test. It's clear why that one doesn't have a UL certification.

    • The Ultra Xconnect [trustedreviews.com] blew up under test. There's a UL marking, but no file number, on the label. Ultra Products has no listings in the UL database. So that's another phony.

    Consistently, every power supply with a valid UL mark passed. And every power supply that blew up lacked a valid UL mark.

    UL tests power supplies by loading them up to their rated load at their maximum rated temperature and running them for hours or days. They also test for safe behavior if short circuited, overloaded, or overvoltaged. They're not concerned with power quality, just safety. The device must not blow up or catch fire, even after a single component failure.

    Report phony UL marks to UL at 1-877-UL-HELPS (854-3577). They arrange for seizure at U.S. Customs, and catch about $12 million a year of hazardous components, which are then crushed.

    • I'm not sure if this is the X-Connect or not, but a keyword search for the product number (X-ULT500P) yields this UL number E126556, which appears to be a 500 watt power supply, but little else is listed.
      • UL says that part number is for a 372.69W power supply made by TAIWAN YOUNGYEAR ELECTRONICS CO LTD. It's not clear whether Ultra resells the unit, modifies the unit, copies the unit, or just uses the same part number. Ultra rates it at 500 watts. They didn't certify under their own name, but put a UL logo on their own nameplate. UL doesn't allow that.

        If you don't see the UL certification number on the nameplate, or it doesn't match the certification database, it's not UL certified. Again, note the st

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