This is kind of a unique test we have worked on for a while.  One of the more important qualities of a power supply is to make sure it does not produce harmful interference to the components.  Perhaps the most sensitive of these components is the memory (video card, RAM, and CPU cache), which is just millions of little transistors locked in an on or off position, held in place only by a delicate balance of electricity. 

The driving theory behind ECC memory is that it corrects errors that occur in memory.  Perhaps a transistor is faulty and flipped for the wrong reason, or a faint electrical signal pulled a transistor into the incorrect position.  While researching this review and others, we have noticed the largest factor for incorrect memory blocks is faulty power supplies. 

How it works:

We started off by modifying MemTest86.  We bumped the delay between tests up to several hours, rather than seconds.  MemTests86 works by writing various patterns into the memory.  After our programmed delay of six hours, the program goes back over the memory and analyzes how many of those bits were flipped out of the original pattern.  Both the memory and motherboard used passed the unmodified MemTest86 without any problems.  

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Not only is this a good measure of shielding on the PSU, but also a good measure of shielding on the motherboard and memory.  However, we used the same motherboard and memory for the entire test.  This way we assure that the small amount of interference coming off the motherboard is consistent with each power supply.  Unfortunately, it took 6 hours to run this test and we ran it three times for each supply to assure accuracy.  On the next page is a table showing the trial data.

Noise Testing Interference Results
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  • Anonymous User - Friday, August 1, 2003 - link

    1. No amp measurements were listed, a serious deficiency because without them there is no way to know how well each PS met its amp specs, and many brands are known to fall short.

    2. No overload testing results for shorts, excessive power draw, excessive temperature.

    3. Ripple is not just slow voltage variation also short term variation, such as for each AC cycle (60 Hz for the incoming AC, about 60,000 Hz for the output DC). I would have liked to see how the latter correlated with the memory noise test results.

    4. I hope you were careful when you tested the PS heatsink temperatures because some heatsinks are live with high voltage.
  • Anonymous User - Thursday, July 31, 2003 - link

    Well for the observent people who can differentiate between orange and blue, its not an issue. Also waiting a full second before clicking it reveals the location on both the bottom left and the mouse cursor. but i can see how it does get annoying.
  • Anonymous User - Thursday, July 31, 2003 - link

    yeah those in page advertisements are REALLY annoying...those have got to go. i never know when i'm going to link to another anandtech article or to an ad...i guess that's the point but it's still unacceptable
  • Anonymous User - Thursday, July 31, 2003 - link

    I would like to see the review include a Heroichi Electronic power supply, I hear they are very good but I haven't used one.
  • Anonymous User - Thursday, July 31, 2003 - link

    Some of your "In Page Advertising" links seem to be missing closing links tags or something so that it results in having a <link> in the middle or end of a sentence. Ex. "We had a lot of troubles with Vantec’s last power supply, the Stealth. We found an error in the production label<link>, which quickly led to a change in all the labeling on all Stealth power supplies."
  • KristopherKubicki - Thursday, July 31, 2003 - link

    #3 and #4, thank you for spotting these errors. I have updated and fixed them.

    Cheers,

    Kristopher
  • Anonymous User - Thursday, July 31, 2003 - link

    I hope the ripple for the PC Power & Cooling 3V wasn't 2.295.. Possibly 3.296??? 1 volt drop is unacceptable.
  • Anonymous User - Thursday, July 31, 2003 - link

    The REAL price of the pc power&coolinghttp://www.directron.com/pcpower.html
  • Anonymous User - Thursday, July 31, 2003 - link

    a little more content per page in some cases would be nice too...

    ...but good to see content on the site at all...and seemingly more regularly too...
  • Anonymous User - Thursday, July 31, 2003 - link

    woah guys, the tables need some work...

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