Introduction

While we've reviewed many higher-end (and higher-cost) power supplies, we've neglected the lower power segment. We hope to address that omission with today's roundup of four units ranging from 400W to 450W. Not many manufacturers these days make units rated at less than 500W - especially if we're talking about high-quality power supplies. Seasonic - both on their own and as an OEM manufacturer - is one of the few companies that continue to supply this market segment. We recently tested Seasonic's 330W and 500W models and found they were more than capable of powering most decent systems. There are far more midrange and lower systems on the market than high-end systems, so we thought it prudent to look at several competing models from other companies.


The type of components used in a computer determines the power requirements for the system. If you want to build an extreme performance, highly overclocked computer then you will need a large (and high-quality) power supply. On the other hand, if you're mostly going to be doing office work, most of the "best" power supplies are complete overkill. In fact, even most higher-end systems rarely require more than 500W of power. So why do we have these 1000W+ PSUs? In a word: profit. Assuming you're not going to be running multiple graphics cards or a significant number of hard drives, one of the power supplies we're looking at today -- or something similar to them -- should be ideal.

Because of the potential for greater profits, power supplies with lower ratings are getting rare -- not many manufacturers that want to produce these units anymore. We talked to Silverstone not too long ago about a 300W version of their Element series. The conclusion was that the price for the production is similar to higher-end power supplies and it wouldn't make sense to build these power supplies anymore. That seems surreal when we think about the number of users that don't need more than 500W, but it appears that the minimum price for a quality power supply -- regardless of wattage -- has bottomed out at around $65. That's not to say you can't find cheaper power supplies out there, but the quality of such units is at best... suspect, as we will see shortly.


As usual, we are testing with our Chroma programmable loads to load each rail to a specific amount. This is important to get truly accurate results and not merely approximate values. We conduct tests in two different temperature environments. One is normal room temperature of 25-26°C, while the second environment goes from room temperature and increases steadily up to 50°C. Especially during the higher temperatures we will see how good the power supplies are and what whether or not they're truly worth your hard-won clams. Components inside will perform much worse at higher temperatures, but we expect any good quality PSU to deal with such test conditions without failing.

On the DC output graphics, we show the range of highest and lowest voltage. There is usually a bit of variance, particularly with multiple 12V rails, but with a PSU roundup we want to convey as much information as possible without simply bombarding our readers with graphs and charts. In essence, we will show the voltage range on each rail at various load points. This is especially easier to read and understand when you have multiple 12V rails since we will show them all in one graph together.

Note: If you would like to know more about our testing methodology, equipment, and environment, please read our PSU testing overview.

Antec Earthwatts 430W
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  • opterondo - Sunday, November 18, 2007 - link

    You all do understand that a 1000w PSU doesn't use 1000w right?

    For instance you hook up 333w peak load worth of components to it it will use ~333w.

    The only reason to buy a smaller capacity PSU is up front price and possibly better AC-DC conversion efficiency (like maybe 70% instead of 60%)
    Reply
  • opterondo - Sunday, November 18, 2007 - link

    Good thing they didn't review any of the COOLMAX PSUs cause they are fairly priced and out perform most any in this article.

    COOLMAX CX-400B ATX v2.01

    COOLMAX CP-500T EPS12V

    COOLMAX CXI-500B ATX12V

    COOLMAX CUG-700B ATX 12V( V.2.2)



    Reply
  • mindless1 - Thursday, November 15, 2007 - link

    Months ago I was almost given a vacation in the forums because of shills and naive owners that wouldn't accept my negative comments about Ultra V-Series. I feel a bit vindicated and yet the review didn't even touch in it's primary weakness, poor capacitors leading to poor lifespan even in a system it would be suited to run in.

    I do have to disagree about one aspect of the review in that the Ultra does have PFC just not active or APFC, and an "old" passive PFC design is not a big deal, a PSU can run fine w/o AFPC and historically there were plenty of decent, not just cheap, PSU with passive PFC evidenced by the input voltage selection switch.

    Also in the reviews, please mention the fans' make model and bearing(s) type as they are also weak links when cheap sleeve-bearing types are used.
    Reply
  • Kougar - Friday, November 09, 2007 - link

    On many of the pages I am seeing empty image placeholders that link to 0x0 pixel images that are 1.5KB in size... someone might want to fix that. :) Reply
  • Christoph Katzer - Friday, November 09, 2007 - link

    Working fine here ;) Reply
  • Kougar - Wednesday, November 14, 2007 - link

    Do you work for Anandtech???

    Since an image is worth a thousand words: http://i111.photobucket.com/albums/n129/Chanur64/M...">Image Link

    The "missing" ghost image placeholder shows up for every PSU info page.
    Reply
  • Christoph Katzer - Thursday, November 15, 2007 - link

    Oh yep thanks. Now it's working. Reply
  • grantschoep - Thursday, November 08, 2007 - link

    Low end power supplies?

    I want to to know who the heck needs a 500+ watt power supply that isn't running some crazy dual SLI setup. I really wish power supply makers would focus on quite and very stable/clean voltages.

    I wish companies would really focus on very high quality low end systems. 98% of us don't need a 500+ watt power supply. 90% of us don't need a motherboard with as much crap as they tack on(2 1gig network ports for example)

    As an electrical engineer, 1 US dollar extra.... could by much better caps and the like.

    Heck as a further annoyance, when company A has a PSU fan that is better/quiter than another, why go whit the lesser

    I really wish that companies would focus on this. I don't need a 1 KW beast. I want a good, high quality ~450 watt supply that is nice and quite.

    Reply
  • erple2 - Thursday, November 08, 2007 - link

    I am a bit saddened by the (IMO) relatively unimportant temperature of the heatsinks, or sound ouput. IMO, the single most important measurement of the usefulness of a power supply is, in fact, it's ability to supply power.

    I would equate evaluating it's value on thermal and acoustic characteristics to evaluating the superiority of a GFX card on it's thermal characteristics. For that effect, my old Matrox Millenium card destroys an 8800GTX.

    Seriously, I'd really like to see much more in-depth analysis and evaluation on the stability of the power generation, the cleanliness of the signal, the resistance to sagging based on varying the power requirements, etc.

    I understand that acoustics and thermals are important, but they're really secondary to the actual performance of the power generation. If you're overly concerned with the loudness of a power supply, or how hot it gets, instead of the actual performance of the power supply, then maybe you shouldn't be using a computer..
    Reply
  • Christoph Katzer - Friday, November 09, 2007 - link

    Did you just read the comparison or? Reply

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