Today, we did something a bit different than our normal reviews and giving you (our readers) a look at a bit of technology related to power supplies. The last time we did this we examined the effect that varying lengths of cables had on the voltage regulation and efficiency of a power supply. Today, though, we are looking at a small piece of test kit that might just save users a bundle by telling them if their power supply is good, or not, in the form of the Thermaltake Dr. Power II. The question is; how useful is the Dr. Power II going to be when it is a $35 PSU tester? Let’s see!

Build Quality

The build quality of the Thermaltake Dr. Power II is reasonable for a $35 unit. It comes clad in a black plastic clam-shell housing and it is equipped with a multi-color LCD screen for reading your results. It has connectors for your EPS connector, PCIe connector, MOLEX connector, SATA connector, and 24pin ATX connector. The system is based on a simple resistor design and it is all run by a Holtek microcontroller. The soldering is very impressive which is, perhaps, a bit of a surprise given the price point but then again shouldn’t be given the simplicity of the design. The documentation that comes with the unit is adequate and it has a three-year warranty from Thermaltake.

Load Testing

With our Phantkes AMP 750 that we tested today we did, indeed, find measurable differences in our voltage outputs. However, there are a number of caveats to that beyond just the statistical issues mentioned previously.

SunMoon SM-8800 versus Thermaltake Dr. Power II Voltage Difference Table

The differences we see between what the SM-8800 and the Dr. Power II give us are large, at times, but there are also two notes to them. The first note is that the Dr. Power II usually only has one digit of precision past the decimal point. So, it may well be missing some changes due to that issue that the SM-8800 is not because of its much greater precision.

The second point of note, here, is that the greater the voltage the greater the divergence in readings (generally speaking). For instance, the 3.3V rail is about dead on while the -12v rail is off in “lala” land. Everyone else is somewhere in between. All things considered, not the best outcome. However, with the price delta between these two units being a bit more than two orders of magnitude; can we reasonably expect a different outcome?

Final Points

Today, the bottom line is fairly simple once more. It costs more than $35 dollars to be both accurate and precise when making test equipment. That said, if you do buy the Dr. Power II to have on hand it will likely do a reasonable job of telling you if your power supply is dead or not.

Beyond that, I would take all of the readings with a heaping dump truck of salt. Is this the worst $35 you would spend on something in your toolbox? Probably not, but if you spent more on a decent voltmeter and you learned how to load your PSU without needing a system to do it you would end up with something that you could use on OTHER things too. If that, however, is not something you are interested in then, at $35, I would probably put that Amazon link into Camelcamelcamel and buy this closer to its historic low of $27.


Paul Johnson

Paul is a long time PC hobbyist and tech enthusiast having gotten his start when he broke his first C64 quickly followed by breaking his first IBM XT. Most notably however, for 12 years, he served as the...

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  1. I got one of these a couple years ago for like $20. It works but there isn’t a lot to it. It did identify a problem with one of my PSU (but I was already 90% sure that one was screwed anyway).

    So for $20 it’s not a bad tool to have to check out PSUs before hooking them up to expensive motherboards. But at $35 I dunno.

  2. Neat little tool, and awesome writeup.

    Yeah, it isn’t much better than a paperclip jumper to see if your PSU is at least turning on – but it does tell you that much in splendid fashion. And for most people at home, that’s really about all you need – does the PSU turn on, and is it close to nominal output? For $35, for a person who puts together machines as a hobby, this is a nice price point and does pretty much what it should. And it’s (presumably) easier to use than a paperclip and gives you a bit more data in the readout (even if it is of questionable accuracy).

    I wouldn’t sell your other test equipment used for reviews though.

  3. Thanks for the article Paul! This is the kind of stuff I see when browsing Amazon, or other places, and wonder if it does anything useful for the money. It may not be able to fully compete on a professional level but at least, for the money, it’s not a total rip-off either.
  4. I really liked this article.
    It’s neat to see somewhat obscure gadgets tested against the real deal.
    This little meter is actually kind of compelling, in a 35 dollar sort of way.
    I always thought the SunMoon almost sounded cult like and mystical, somewhat like power supplies……..
  5. I have an ancient Antec power supply tester and it has been very useful over the years. It just has pass/fail LEDs and an overall Fault/Good reading. I always use it to test a power supply (new or repurposed) before installing, and it has saved me a few times.
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