Part 2: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed

By Patrick Afschar
published

Ready for part two of our low-cost power supply round-up? Here are four more products, including Seasonic's SSR-360GP, which is 80 PLUS Gold-certified. Is this little 360 W PSU the bargain of the century, or is its Gold label simply pyrite?

Corsair CX500: Measurements

Efficiency According to the 80 PLUS Spec

Efficiency by Load

Corsair’s budget-oriented PSU passes our lab tests with nary a hitch. When we check the efficiency, we find that the CX500 not only complies with 80 PLUS' Bronze spec, but has some leeway at medium and full load. Even operating at a low load, it is quite efficient (80% at 50 W, for instance). Measuring ripple and noise, the PSU not only complies with the ATX spec, but surprises us by keeping those brief spikes inside the specification as well on its 12 and 3.3 V rails.

When we disregard the spikes, the ripple and noise values are excellent. Standby power draw and inrush current are among the lowest in our field of contenders. But when we measure hold-up time, which protects against brief brownouts, we saw a result shorter than 16 ms, which is the ATX specification's floor (we saw 14 ms at both 115 and 230 V). At 31.5 dB(A), this PSU is insignificantly louder than Cooler Master's Silent Pro M2.

A Close Look at the PCB

When we spot the green transformers, we immediately know that Corsair's CX500 is manufactured by Channel Well Technology. The interior layout is very clean and the soldering quality is excellent. The large capacitor on the primary side is manufactured by Samxon, which is part of the China-based Man Yue Technology holding. On the secondary side, there are also some Samxon capacitors, but also some capacitors manufactured by Teapo in Taiwan. In spite of its low price, no important components fall victim to cost cutting. For instance, the input filter sports two X capacitors and four Y ones, two coils, and a MOV.

Patrick Afschar
59 Comments Comment from the forums
  • Deemo13
    You guys aught to make a power supply hierarchy chart.
    Reply
  • pepsimtl
    Please, if you could say , if the power supply is compatible with Haswell .I think this is very important .
    Reply
  • benedict78
    I second that request. Does ANY of those PSUs support the new Haswell C7 state?
    Reply
  • ojas
    There's also a CX500M...
    Reply
  • jeffunit
    I am not sure why you think that a 40w bulb is purely resistive. Almost all bulb filaments are coiled, which makes them inductive. For example, http://www.donsbulbs.com/cgi-bin/r/b.pl/h4652|12.8v|40w|60w~usa.html shows a 12v 40w bulb filament, which is coiled.

    Perhaps you should measure the inductance of your bulbs, rather than just stating they are purely resistive.
    Reply
  • vertexx
    A couple different PSUs for different applications. I use the Corsair CX 430 & 500 for budget gaming builds, and just this week I ordered the Seasonic for the first time for a home server build. Nice to see those choices validated.

    Thanks guys, nice article!
    Reply
  • Someone Somewhere
    In spite of its low price, no important components fall victim to cost cutting.

    In the CX500. I think Samxon caps count as cost cutting.
    Reply
  • flong777
    I have recommended the CX500 many times to budget builders and now I feel better about it. It is the clear winner. Funny TH says it is loud but it was nearly identical to the CM 520 on their chart in DB noise.

    On sale you can pick up the CX500 for $40 which is about as cheap as you will ever find any PSU. If you compare how well that Corsair backs its products, there really is no comparison - Corsair is the only choice.

    As far as the Seasonic 360, why on earth would you buy a 360W PSU? I just don't see the point. While I can justify a 500W PSU to a budget builder, I really cannot comprehend recommending a 360W PSU to anyone. I feel cautious with a low wattage 500W PSU. All of these PSUs will run hot and loud if they are stressed and so moving up to a 650W or even an 850W PSU really is not that more expensive.

    I got the gold rated 850W Corsair HX 850 for $144.00 on sale. I can not even begin to describe how excellent this PSU is. It runs as something around 92% efficiency under load and I have never hear the fan even come on (it may be that low fan is inaudible). It comes with a 7-year warranty and is modular.

    If you are not strapped with a low budget, moving up is the only way to go. If you are, the CX 500 is a good choice.

    Reply
  • vertexx
    11443584 said:
    As far as the Seasonic 360, why on earth would you buy a 360W PSU? I just don't see the point. While I can justify a 500W PSU to a budget builder, I really cannot comprehend recommending a 360W PSU to anyone.
    I just ordered the Seasonic for a home server build. The higher efficiency is a plus since it will be running 24x7. Plus, the system really doesn't need the extra wattage.

    PSUs run more efficiently under load. IMO, the trend has been to overkill on the PSU when it's not really needed. In reality, when you actually add up the max loads of all components a 350-450W PSU is more than enough to run most single GPU gaming builds.
    Reply
  • vertexx
    11443366 said:
    I am not sure why you think that a 40w bulb is purely resistive. Almost all bulb filaments are coiled, which makes them inductive. For example, http://www.donsbulbs.com/cgi-bin/r/b.pl/h4652|12.8v|40w|60w~usa.html shows a 12v 40w bulb filament, which is coiled.

    Perhaps you should measure the inductance of your bulbs, rather than just stating they are purely resistive.
    It's been a while since I've been involved in DC power calculations, but these bulbs are DC bulbs. At DC steady state, what role does inductance play?
    Reply