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Thread: silentpcreview.com/A_Better_Way_to_Compare_PSU_Efficiency

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    Default silentpcreview.com/A_Better_Way_to_Compare_PSU_Efficiency

    http://www.silentpcreview.com/A_Bett...PSU_Efficiency

    nice charts on lower wattage comparison.

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    Doesn't it mean they just subtract DC power from AC power, instead of dividing one by the other? As in, one mathematical operator of difference?

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    First of all you have to test different power supplies at the same load level to collect the original P_in & P_out data, and then it's just a different way to process those data.
    It's been a hard day's night and I've been working like a dog.

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    Very interesting.

    "Conclusion: NOT buying more wattage than you need can lead to higher efficiency."

    Though he didn't write that specifically.
    Zap
    Clan of the Bloody Fist

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    It is worth noting that their tester, like mine, is analog and resistor based. Higher voltage than 12v means more current than their load tester's labels say there is. Lower voltage means less of course. They don't mention whether that's dialed out in the charts or not that I can see. It's only an issue (IMO, anyway) for efficiency calculations.

    It's an interesting way to look at the data, I enjoyed reading it.

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    they probably use a multimeter or something similar to get the exact volt measurements on all rails, in order to calculate the DC load and get efficiency right.

    If you want to monitor many analog outputs on the same time use a device like Labjack. They are easy to set up and have very good accuracy and fast enough DAC.
    Now to measure the Amps you can do it again with a Labjack, some shunt resistors and a couple of op-amp amplifiers. Basically the pain is to measure the Amps right.

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    That's what I'd figure, if they're correcting for it. I assume they are as efficiency numbers without correction are dubious at best.
    That's why I don't go into efficiency much, with numbers anyway.

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    Well, I am not concerned so much with the absolute accuracy.

    It is more the difference between the best and worse at certain level...
    When you say 85% bronze verses 90% gold..it seems rather small potatoes.
    However when you see on the chart you could either be wasting 5 or 40 watts...well that's a significant difference.
    Perhaps not enough to justify a huge increase in price, but certainly significant.

    Just a different perspective on the same numbers.

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    Quote Originally Posted by Zap View Post
    Very interesting.

    "Conclusion: NOT buying more wattage than you need can lead to higher efficiency."

    Though he didn't write that specifically.
    Well I think it looks all over the map. What I see is newer more efficient is much better in power loss and the differences between models of different maximum load isn't that significant. But I haven;t thoroughly untangled the vintage from the wattage/

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