No-name brand PSUs vs Known Brands: MAD testing

Cases & PSU/Power Supplies by jmke @ 2008-11-28

We were invited to visit Cooler Master´s brand new power supply testing setup, a very high end installation build to deliver up to 1200W and higher load to any PSU hooked up to the system. We bought some cheap PSU units from local Belgium stores to see how they would measure up when stressed to their rated wattage... read on to find out about the carnage.

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Stability Power put to the test

Stability Power 450~500W

This power supply is as generic as can be, dull grey color, one specification label for all different models, ranging from 300 to 550W.

There are not a lot of connectors on this PSU, hardly enough to power a very low end system, don’t try to use for a new Intel or AMD system though, there’s no 8-pin power connector or 6-pin PCIe. This unit is for Pentium 4 and Athlon XP…

Madshrimps (c)

The all in one label shows maximum loads for each volt rail:

  • +3.3v: 28A
  • +5v: 38A
  • +12v: 20A
  • -12v: 0.8A
  • +5VSB: 2A

    Older generation system did get CPU power from the 5v line, this explains the overpowered +5v and the underpowered +12v.

    Madshrimps (c)

    Our first test is loading the PSU up to almost 50% of rated capacity:

    Madshrimps (c)

    The efficiency is respectable at 77%, the voltage lines remain quite stable too, not too much deviation seen. The power factor is low, 0.57 (57%), most brand name units hit 90%+ numbers with ease.

    Let’s try for close to 75% load:

    Madshrimps (c)

    Efficiency drops noticeably; to be able to output 361W we are drawing 533W at the wall outlet. The 12v rail drops quite low, while the -12v is up, clear signs of instability.

    Do we dare to increase further? We didn't quite reach 100% load.

    Madshrimps (c)

    We increase the load on the 3.3v and 5v rails, the outcome is bad, quite bad, efficiency drops to 66% and we’re at the maximum of what this unit can take, after 5min we heard a buzzing noise followed by a loud pop and visible smoke, the Stability Power was dead. The numbers you see above are far from encouraging, the -12v line is way up, and while this unit is rated for 450~500W it doesn’t even come close to reaching 400W.

    Madshrimps (c)

    One dead, one to go, will the Sweex survive the tests ?
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    Comment from thorgal @ 2008/11/28
    Great article and a big thank you to Coolermaster !
    Comment from Rutar @ 2008/11/28
    indeed a great article