Sign in with
Sign up | Sign in

Part 1: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed

Part 1: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed
By

Power supply manufacturers condition us to think that efficiency is the one variable you need to pay the most attention to. But we have a suite of tests that more thoroughly taxes PSUs. Can these four inexpensive units under $70 make it through unscathed?

While we all love the latest, greatest, and fastest hardware, it's just as important to us that the more affordable, accessible components perform well. Today is the first story in a two-part series where we round-up power supplies you might find in the bargain bin of your favorite online store. We asked each vendor to send us samples with 80 PLUS Bronze ratings or better, selling between $45 and $70.

In this piece, we have power supplies from Antec, Chieftec, Cougar, and Enermax. The second part will include Cooler Master, Gigabyte, OCZ, and Seasonic.

This time around, we're looking at output ratings ranging from 350 W (Cougar A350) to 550 W (Chieftec Nitro 2). Each of the four models features an 80 PLUS Bronze rating, which means that they should all achieve at least 82% efficiency at 100% and 20% load, and 85% efficiency at medium load. 

Unfortunately, not all of these units are available in the U.S., which makes price comparisons difficult. The Antec HCG-400 goes for around $45 though, which is pretty reasonable for a 400 W power supply.

Updates to Our Testing Methodology

Based on reader feedback, we're including acoustics in our testing suite. You'll see us do this moving forward, employing three load levels: 40 W as a simulation of an idle PC or a system engaged in light office work, 200 W for a medium-grade gaming PC, and 600 W for a high-end gaming PC. When 600 W is more than the maximum allowable combined load on the PSU’s 12 V rail or rails, we skip this test and make do with the other ones.

In order to simulate various loads, we built a test rig consisting of fifteen 12 V/40 W light bulbs. Thus, we can apply any load from 40 W to 600 W to the 12 V rail of a power supply, and it's guaranteed to incur no phase shift, since the load is neither inductive nor capacitive. As DC-powered light bulbs are perfectly silent, this is also a good way to measure sound levels without a lot of ambient background noise. We measured sound levels a foot away from each PSU's fan, and gave the power supplies 30 minutes to achieve an equilibrium after setting a new load level.

A Brief Remark about a Measurement Anomaly

All of the PSUs in this round-up exhibited a strange phenomenon during the ripple and noise test, which baffled us. They showed a strikingly similar pattern of spikes on the oscilloscope screen during the ripple test, causing all PSUs to fail that metric. Typically, this would lower each power supply's score. But because we knew it'd be unlikely for every make and model to suffer from the same design or manufacturing defect, we took a closer look at our test setup. We even asked Enermax and be quiet! to help us troubleshoot the issue with their equipment. The spikes didn't happen in either vendor's lab. So, after examining our test equipment, our cabling, and our test methodology, we were finally able to explain this annoying issue.

Recently, we swapped out the Tektronix DPO3034's probes with newer and supposedly higher-quality replacements. As soon as we switched back to the old probes, the spikes disappeared. It'd be natural to suspect that the new probes are defective. However, we've tested higher-end PSUs like Corsair's AX1200i with the new and old probes, and never saw any spikes.

After testing and retesting, we concluded that the brief spikes are real and are not caused by faulty test equipment. In fact, they could be caused by the probes having a wider bandwidth range. We deem them irrelevant to judging these PSUs, and we're disregarding them as we evaluate ripple voltage, though our screen shots and benchmark analysis do document them. After all, it's conceivable that even short spikes degrade or even damage some PSU components over time.

Display 56 Comments.
Top Comments
  • 10 Hide
    envy14tpe , August 27, 2013 10:37 PM
    This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...
Other Comments
  • -4 Hide
    wolley74 , August 27, 2013 9:04 PM
    no love for the EVGA 500B?
  • -8 Hide
    computer_nugget2 , August 27, 2013 9:20 PM
    ALWAYS judge a power supply by its weight. especially if its Chinese.
  • 8 Hide
    InvalidError , August 27, 2013 9:31 PM
    Quote:
    always judge a power supply by its weight.

    Some Chinese OEMs put rocks, small concrete blocks, lumps of steel or other stuff like that disguised as a transformer with bits of wire that aren't connected to anything to trick people into believing their heavier PSUs are better.

    So weight alone is not a reliable indicator.

    Also, at high frequencies and high efficiencies, the size of inductors, capacitors, transformers and heatsinks along with the associated weight shrink. While light weight and high quality may rarely be seen together, they certainly are not mutually exclusive.
  • 2 Hide
    dudewitbow , August 27, 2013 9:38 PM
    Quote:
    no love for the EVGA 500B?


    a good chunk of Tom's physical hardware reviews generally are conducted in europe. This goes for a good handful of the gpu tests as well. EVGA rarely ever shows up on review sites because of it(and possibly due to lack of EVGA response to a hardware review pitch)

  • -6 Hide
    computer_nugget2 , August 27, 2013 10:03 PM
    Quote:
    Quote:
    always judge a power supply by its weight.

    Some Chinese OEMs put rocks, small concrete blocks, lumps of steel or other stuff like that disguised as a transformer with bits of wire that aren't connected to anything to trick people into believing their heavier PSUs are better.

    So weight alone is not a reliable indicator.

    Also, at high frequencies and high efficiencies, the size of inductors, capacitors, transformers and heatsinks along with the associated weight shrink. While light weight and high quality may rarely be seen together, they certainly are not mutually exclusive.


    do you have pics to prove this?
  • 10 Hide
    envy14tpe , August 27, 2013 10:37 PM
    This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...
  • 4 Hide
    jimmysmitty , August 27, 2013 10:42 PM
    Quote:
    This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...


    They have already listed the PSUs for part 2 and I didn't see a part 3 listed. I wonder where the Corsair CX430 is. Its a 85+ Bronze PSU and is $39.99 on Egg right now. Its one of the best entry level PSUs I have actually used as well and compared to other PSUs at the same price point or higher (within 550W and may or may not be 80+ at all) I have seen less of them come back bad.
  • 5 Hide
    razor512 , August 27, 2013 10:47 PM
    Quote:
    always judge a power supply by its weight.


    While weight is an important factor, overall weight is 100% useless

    for example check out the SIGMA SHARK SP-635

    http://www.ocia.net/reviews/sigma635/page2.shtml

    it is probably one of the heaviest power supplies you will find (with the exception of some of the 1200 watt ones)

    I purchased it a while back and was disappointed at the internals. they used an insanely thick case that made the power supply weigh a lot but the insides were were the result of the owner of the company asking while walking around china, what are the cheapest items we can find on the shenzhen market today.

    (at least the power supply can double as a flail or a boat anchor)
  • -2 Hide
    pyro226 , August 27, 2013 10:47 PM
    Hoping to see the CX430 and other corsairs reviewed. I like the little thing since it powers my PC. :D  It originally rang a bit when the computer was suspended or at random after a few hours of use, but that went away with age.
  • -2 Hide
    sanilmahambre , August 28, 2013 12:13 AM
    Nice basic testing method
  • 2 Hide
    benedict78 , August 28, 2013 12:31 AM
    One very important question is not answered in this article. Do any of those PSUs support the new Haswell C7 state? Anyone who's buying a new Intel 4xxx processor should know if his PSU is compatible with the CPU.
  • 1 Hide
    PreferLinux , August 28, 2013 2:22 AM
    Could you do a shot of the spikes using a sweep time of 1 us/div, or even less, in the next part please (assuming you get them)? And maybe one that shows a single cycle of the PWM switching (clearly defined on some of these)? It'd be really interesting – I've got some theories about what is causing it, but nothing concrete yet...
  • 2 Hide
    butremor , August 28, 2013 3:04 AM
    Who's Who In Power Supplies
    Really useful article, let's you look for reviews of PSU real manufacturer if needed.
  • 5 Hide
    Someone Somewhere , August 28, 2013 3:21 AM
    How are you loading the minor rails? Loading 12V only will unfairly penalise group regulated designs, which do much better with even a little load on 5V/3V3. Systems still have some load on 5V/3V3, usually things like audio chips on the MB and HDD/SSD electronics.

    I'm waiting for the XFX 550W - those go for about $55 (seems to be $62 now), and are supposedly pretty decent.

    EDIT: On further reading, you've got a pair of Chroma load testers - so what are the bulbs for?
  • 0 Hide
    Someone Somewhere , August 28, 2013 4:24 AM
    And for the most part are very close to THD=0. Which is a resistive load.

    (Hint: Capacitors and inductors balance out.)
  • 0 Hide
    vertexx , August 28, 2013 4:57 AM
    Why no Corsair? Seems like a pretty big omission - I'm sure there's an explanation, but it would be helpful to understand why? The Corsairs have to be one of the top selling PSUs right now due to their aggressive pricing and general perceived quality. It would be really good to know how these match up, because they are right now my "go-to" brand for budget PSUs.
  • 0 Hide
    Someone Somewhere , August 28, 2013 5:06 AM
    Less than, but generally rather close. Besides, capacitance actually makes them work better - smooths out ripple.

    See the 'Part 1'? Probably going to be more later.
  • 2 Hide
    InvalidError , August 28, 2013 5:40 AM
    Quote:
    do you have pics to prove this?

    Search for "Fake PFC transformer"

    Here's a page with a bunch of examples:
    http://www.pcpop.com/doc/0/294/294565_all.shtml

    Granted, they are all brands almost nobody knows. Hantol isn't on the list above and seems to be the only other manufacturer who's been caught doing this.

    My point simply was: it is known to have happened.
  • 1 Hide
    InvalidError , August 28, 2013 6:03 AM
    Quote:
    Resistive load has power factor of 1. DC-DC converters have power factor of less than 1.

    Actually, DC-DC converters have no power factor in the conventional meaning of the term whatsoever since power factor is used to represent the discrepancy between AC voltage and current which itself is a combination of phase shift and distortion factor intended to represent how much unlike-a-resistor an AC load is.

    DC-DC converters are roughly constant-power load and aside from inrush while their input and output caps get charged and load changes, they are practically indistinguishable from resistive load to the upstream AC-DC or DC-DC converter as long as it has enough local decoupling to remove most of the switching noise and ripple.

    If you were to calculate the "power factor" of DC-DC converters which basically boils down to determining how much power gets transferred at 0Hz vs any power exchanged at frequencies above that since there is no phase to worry about at 0Hz, you would find out DC-DC converters are indeed very close to 1.
  • 0 Hide
    Someone Somewhere , August 28, 2013 6:16 AM
    Yup.

    There is, however, a term called 'total harmonic distortion', which (IIRC) refers to the amount of noise produced by a device.

    You can basically treat any load as resistive in DC though - the ripple is barely noticeable (<5%) vs more than twice RMS voltage for AC. And it only occurs on the ripple.

    I can probably scrounge some stuff out to test it though, but it's not really necessary.
Display more comments
React To This Article