When it comes to power supplies for silent computing, there's one name that always comes up: Seasonic. Seasonic was originally an OEM PSU manufacturer, and they had a reputation for producing good quality, high efficiency products. It is unusual for an OEM manufacturer to bring their own products to the market since there are usually several competitors already using the same power supply. That's why it wasn't until 2002 that Seasonic decided to enter the retail market. The first power supplies had some difficulties: they came in a grey housing, there were no cable sleeves, and in contrast to many other high-end power supplies at the time there were no LEDs (Gasp!). All that customers got was a very simple looking power supply with limited to no features. The fact that Seasonic was ahead of the rest of the market in producing high quality, good efficiency PSUs with stable DC outputs wasn't clearly visible in the beginning, and few people actually knew enough about power supplies to look for those attributes.

Seasonic has traveled a long and winding road since then, and their marketing department wasn't much help. Today, Seasonic remains a very odd company in many respects, and it is difficult to compare them with many of their competitors. The size of the market for Seasonic products doesn't seem to matter; the company seems unconcerned with expanding their production facilities to meet market demands. Instead, management focuses on things like the development of newer and better products, preferring quality to quantity. That doesn't mean Seasonic is small, however; they manufacture many high-end, well known brands like Antec, Corsair, and PC Power & Cooling to drop a few names.

Of course, being manufactured by Seasonic doesn't necessarily mean that all of the brands are equally good. The consumer needs to understand that the Seasonic customer will only get the quality they can afford -- or the quality they ask for as the case may be. For example, a certain company delivered cases with pre-installed Seasonic power supplies (branded with their own name), and many of these power supplies went up in flames after a short period of time. Huge RMAs resulted from this, naturally, proving that there's a distinct difference between a Lexus and a $5,000 "luxury car" manufactured at a Lexus plant. As usual, you get what you pay for, and by refusing to pay for Seasonic quality the client received an inferior PSU. We're not here to talk about Seasonic's strategies and past business behavior, however, but rather we are here today to take a look at the new Seasonic S12II series, their latest product for the retail market.

The S12II series comes in four different wattages: 330, 380, 430 and 500. With these lower wattage power supplies, Seasonic is catering to the market where they built their reputation: silent computing. Expectations for their latest design will be high, given how popular the previous S12 and M12 series have been, both of which were huge successes for the company. The S12II features and new PCB design, though of course Seasonic seldom develops a completely new PCB layout. In most cases companies will take an older design and enhance it. (Seasonic's new X900 for example is based on a 2-year old PCB design.) This isn't necessarily a bad thing, especially if the original design is good, and Seasonic has a reputation for delivering some of the best quality power supplies on the market. That's a big compliment for any company, so let's see if Seasonic is worthy of such praise.

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  • n0nsense - Sunday, September 16, 2007 - link

    Btw, can you add 1 minute record of ambient, idle PSU, typical load PSU and full load PSU noises @ ~1 meter ?
    this will be much more useful then just dba levels.
  • vijay333 - Friday, September 14, 2007 - link

    lol. so many people requesting seasonic reviews lately and not a peep from them yet. these units are probably suited for budget systems but the added expense due to the seasonic moniker may be better applied to future-proofing and getting a higher wattage model from a less "esteemed" brand. Reply
  • yyrkoon - Saturday, September 15, 2007 - link

    Not everyone requesting a review HAS to comment on the review. I could have been the first poster in this comment section on this article, but decided that the article was good enough to not comment. Granted I think for a lowly 500WATT PSU the Antec Earthwatts 500 PSU would be a better bargin(which I already own).
  • customcoms - Friday, September 14, 2007 - link

    I'm waiting for a Corsair review from you guys, since they are based off Seasonic psu's and can provide higher wattage. Also, people looking at the Seasonic 500w model would also probably be looking at the Corsair HX520.

    My HX520 is silent (granted I have like 8 case fans+cpu+ram+8800GTS, so noise of the psu is of little concern) and as an added bonus its modular.
  • kmmatney - Friday, September 14, 2007 - link

    There is a new 550W Corsair available now, at a lower cost:">
  • Christoph Katzer - Friday, September 14, 2007 - link

    Will have Antec and Corsair very soon but I can tell you already they cannot stick up to the originals. Reply
  • n0nsense - Sunday, September 16, 2007 - link

    as I can see, Corsair HX520, HX620 are better.
    the 12V much more stable + modular cables + 0 noise.
    but may be the Corsair's VX (budget) should be reviewed too.
  • Chunga29 - Friday, September 14, 2007 - link

    I want to see one of the X900 Seasonic PSUs tested now. See how Seasonic does when they have to deal with about 2X the power demand. Though, that design looks completely different so I expect silence isn't the goal in that case. Seeing the M12 700HM results would also be useful. The S12II is at 28dB at full load, but dealing with another 200W could mean quite a bit more noise.

    I would also be curious: can these PSUs handle higher loads than rated? I mean, I've heard rumors that something like a Seasonic 330W sold under a different label would get rated probably ~25% higher, so maybe 420W. That would make the S12II 500W potentially equal to other ~650W PSUs, *if* there's any truth to the stories. Just a thought, but I'd like to see testing push PSUs beyond the rated output to see what happens. Probably best to save that testing for the end, in case the PSU dies. LOL. But going 20% beyond the rating could provide interesting results.
  • Christoph Katzer - Friday, September 14, 2007 - link

    I was thinking about to add this kind of test. Last week I was talking to Paul from H about it and just for fun tested the Infiniti and got 1000 watts of load out of it. That might be surely a nice thing if more PSUs would perform like that. Reply
  • poohbear - Sunday, September 16, 2007 - link

    chris are u saying the corsair hx series (which are designed by seasonic) can't measure up to original seasonics? they're pretty bad ass psus, i own the hx520, i can't imagine anything more silent than this unit?! or are u talking about efficiency? anyways, thanks for the review, seasonic rocks and my corsair is testament to that..:) Reply

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