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Soon At Tom's Hardware: Full-Scale Power Supply Testing

Soon At Tom's Hardware: Full-Scale Power Supply Testing
By , Patrick Afschar

Often overlooked, the power supply unit (PSU) plays a crucial role in supplying the PC with stable and sufficient power. Whether you only need a 300W PSU for a modest small form factor box or a 1,200W model for a gaming juggernaut, the quality of your power supply will not only affect the system's performance, but also its longevity.

Bad power can mean early failures...and there are plenty of bad PSUs out there waiting for the unwary. This is why we felt it necessary to start testing PSUs in order for our readers to make better component decisions.

Test equipment plays an important role when evaluating power supplies though, which is why it's such a difficult job to do properly. Only with the help of highly precise measurement instruments can we document the differences between comparable models in an objective and reproducible way. Tom's Hardware performs all of these tests in professional labs, just like the ones found in PSU manufacturing facilities, where we get access to equipment from Chroma. For those new to this space, Chroma is the de facto vendor of PSU testing equipment.

When testing, we measure the following details:

  • Standby power consumption at 230V
  • Inrush current at 115V and 230V
  • Energy efficiency at 20, 50, and 100% of the stated maximum sustained load at 115V and 230V (according to the 80 PLUS consortium's certification)
  • Energy efficiency at 25W, 50W, 85W, 300W, and 500W of power draw at 115V and 230V
  • Hold Up Time after losing power input at 115V and 230V
  • 12V rail overload test at 110% of the specified maximum sustained load
  • Short circuit test at 115V and 230V
  • Measurement of the temperature difference between intake and exhaust air (maximum delta) at 115V and 230V


In addition to the above mentioned values, Tom's Hardware also takes into account the ergonomics of the PSU and its accessories. This includes features like the the length and design of the cables, cable modularity, and any useful accessories. All important technical data will be presented in a table.

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  • 33 Hide
    Gamer-girl , June 22, 2010 6:24 AM
    Is it possible to include sound levels in decibels?
  • 27 Hide
    JonnyDough , June 22, 2010 6:34 AM
    I second what gamer-girl said, and although this is exciting I'm still awaiting the Graphics Comparison Charts! I realize this is more of an IT website, but these days everyone's a gamer of some type! Long live PC gaming!
  • 17 Hide
    baracubra , June 22, 2010 6:37 AM
    Wow, great idea and article! This will be a huge help and I'm glad u guys took the time and effort to put this together! Long live TH!
Other Comments
  • 33 Hide
    Gamer-girl , June 22, 2010 6:24 AM
    Is it possible to include sound levels in decibels?
  • 27 Hide
    JonnyDough , June 22, 2010 6:34 AM
    I second what gamer-girl said, and although this is exciting I'm still awaiting the Graphics Comparison Charts! I realize this is more of an IT website, but these days everyone's a gamer of some type! Long live PC gaming!
  • 17 Hide
    baracubra , June 22, 2010 6:37 AM
    Wow, great idea and article! This will be a huge help and I'm glad u guys took the time and effort to put this together! Long live TH!
  • 13 Hide
    Anonymous , June 22, 2010 6:42 AM
    take the good ideas from some other nice psu reviewers

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=153
  • 3 Hide
    joytech22 , June 22, 2010 6:50 AM
    I hope they do a large comparison, i want to see how my Antec TPQ 1Kw stacks up to some of the other manufactures.
  • 3 Hide
    baracubra , June 22, 2010 6:53 AM
    Btw, how much did all this eqipment cost TH??
  • 3 Hide
    Anonymous , June 22, 2010 7:15 AM
    This is great news. On a related note do you guys not do LCD monitor testing anymore?
  • 4 Hide
    gege , June 22, 2010 7:42 AM
    take the good ideas from some other nice psu reviewers [2]

    www.hardwaresecrets.com/page/power
  • 2 Hide
    liquidsnake718 , June 22, 2010 7:46 AM
    Bravo, good choice for a new section as more consumers and buyers should be aware of the power supplies and the quality/preformance that they offer us. I myself am about to change my older PSU and will be waiting to read the first comparisons. The problem is, which ones will you choose and every month will you have a power category? For example all the 500-600watts, then following the 700-800, 1000w onwards, ect.

    You might even succeed in killing off generic psu's or at least make more ppl buy 80 plus or 80plus bronze psu's....
  • 2 Hide
    Henry Chinaski , June 22, 2010 8:42 AM
    It's a very good news. Another qualified reviewer is always welcome.
  • 4 Hide
    KingArcher , June 22, 2010 9:09 AM
    This is an awesome setup. Wish I worked at TH.
  • -2 Hide
    neiroatopelcc , June 22, 2010 9:31 AM
    Article500W: Gaming PC with a high-end CPU and multiple graphics cards

    I've measured my system using 750W, and that's definetly more than 500W draw on the inside. And considering my system's only got two harddrives and air cooling, I'd say 500W doesn't qualify as high end cpu with multiple graphics! 600W at least!
  • -6 Hide
    Reynod , June 22, 2010 9:52 AM
    Great news.

    We should of course give the reviewer the nickname "Scotty" ... surely?

    The PSU is technically "engineering" and ratings should include references to "warp factor" and dilithium crystals" ...lol.

    Nice test gear there ... good looming job too.

    Looking forward to some definitive reviews now you have the gear.

    I am wondering how some of the vanilla PSU's will go against the more expensive units?

  • 1 Hide
    gustavost , June 22, 2010 10:13 AM
    I can't barely wait for the test!

    It's really nice that we as customers have real test we can rely on!
  • 0 Hide
    feeddagoat , June 22, 2010 11:08 AM
    Bit-tech/CPC already do something like this. Its by far the best way to test PSU's and its fantastic that Tom's is doing something similar. Can I suggest a comment on fan noise as well. bit-tech comment on the loudness of the fan at full load but don't actually do any sound measurments due to background noise in the offices. Better than nothing tho. Also is there anyway to "endurance test" a PSU. A few PSU's end up in secondary PC's, it would be nice if there was someway of testing long term strain on PSU's too.
  • -4 Hide
    7amood , June 22, 2010 11:19 AM
    YESSSSS PLEEEEEEEEEEEEEEASE \^_^/
  • 8 Hide
    allantang , June 22, 2010 11:56 AM
    I wish there were more info on this stuff, so this would be great!

    I think room temp should also be taken into account. It will make a huge difference if the room is 15C or 25C.
  • 0 Hide
    JohnnyLucky , June 22, 2010 12:13 PM
    Great news! Looking forward to reading power supply reviews. Glad to know you will be testing overload and short circuit protection.
  • 4 Hide
    saifallofjmr , June 22, 2010 12:19 PM
    Also please do the green series by rosewill so we can finally confirm whether or not this brand is in fact good or really bad.
  • 0 Hide
    elel , June 22, 2010 12:37 PM
    Good job. Another thing that I think would be VERY useful would be to test the current drawn from each rail by the SBM PCs. I know that you test system wattage already but I would like to see how much current of each voltage they draw, possibly taken from a custom modded high wattage PSU like the one x-bit made for similar measurements.
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