It has been 16 months since our last power supply review, but the long wait is finally over. We have a new PSU and cases editor, and this is the first of many new PSU reviews to come. The first PSU to hit our new testing lab is the S12G 650W from Seasonic. Seasonic is a company that hardly requires any introduction; they are one of the oldest and most reputable computer PSU designers, manufacturers and retailers. Today, their products are held in very high regard by experts and enthusiasts. The company has their own retail range but they also serve as an ODM for many other well-known brands.

The target groups of the S12G series are advanced users, enthusiasts, and generally those who are not afraid to pay a bit more for advanced performance. It has impressive specifications and features, including an 80 Plus Gold efficiency certification and a "Smart and Silent Fan Control", as well as a five-year manufacturer's warranty. Despite that, it does not really break the bank, as the 650W version that we will be testing today retails for $89.99 plus shipping, a price that appears quite reasonable for such a product.

A year or two ago, you would have had a hard time trying to find a high quality 80 Plus Gold certified unit for that kind of price; however, today Seasonic's retail range has tight competition from several other manufacturers, such as Antec, EVGA, Rosewill, and others. As the Seasonic S12G is not a modular unit and doesn't really include any special features, the company clearly relies on quality and performance above all else; middling quality and average performance cannot be tolerated when several other manufacturers are breathing down your neck. Let us see if the 650W version of the S12G can live up to Seasonic's reputation.

Packaging and Bundle

Seasonic supplies the S12G PSU inside a fairly well designed cardboard box, with a black/blue color theme. The front of the box is tidy, with just a few badges with the certifications of the unit on display. The sides and rear of the box however are littered with information about the unit, in several languages.

Companies rarely supply anything noteworthy alongside their PSUs, especially the non-modular models, but the Seasonic S12G appears to be an exception. Besides the usual power cord, manual, and screws, Seasonic also includes a few cable ties, three blue/black velco cable straps, and a case badge with the company's logo.

The Seasonic S12G 650W PSU
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  • platos - Saturday, March 1, 2014 - link

    I also want to see low wattage small form factor PSUs like the picoPSU and compatible bricks. I'm personally moving away from large desktops for my DIY PCs. I'm even hoping for pico and nano-ITX boards and cases to become popular.

    I'm guessing large desktops will mostly be confined to companies in the near future and they are more likely to buy PSUs as part of a complete system so they wouldn't directly care about individual PSU ratings.
  • E.Fyll - Saturday, March 1, 2014 - link

    " My homeserver is pulling 35W from the wall right at this moment. "

    If you are not using a true RMS meter to read this figure, I am afraid that your actual power draw is way off. Especially with the PSU that you are using.
  • Daniel Egger - Sunday, March 2, 2014 - link

    Actually that's what my APC UPS tells me which is also continuously read out so I also know the load profile over time and can even correlate with the temperature.

    Not too much of a fan reconnecting 24/7 servers too often from the mains just put different power reading hardware in between I must say.

    From what I can tell the readings from the UPS is quite accurate: I've tested it with a variety of computer and other IT equipment using switching PSUs with a true RMS meter in between.
  • E.Fyll - Sunday, March 2, 2014 - link

    The UPS has no true RMS reading, sorry...
  • emn13 - Saturday, March 1, 2014 - link

    It's the GPU's that are costing you. I've got a standard voltage, overclocked 4770k which is currently fully loaded and it's using 97W at the wall outlet; it idles at 20W - that's including power supply overhead. With some undervolting rather than overclocking I can get that down to 15W, with 1HDD and 3SSDs, but my motherboard isn't very friendly to undervolting so I decided it wasn't worth the bother.

    A single GPU, even if it's not the top of the line, can easily consume more than the entire rest of your system. You say you have two GPU's? Well, there you go: 20W for the base system, 20W for each GPU and you're in about the right ballpark.
  • mike55 - Friday, February 28, 2014 - link

    Excellent article! I would definitely be interested in seeing an article about how to choose the right PSU. There is a lot of information out there, but a lot of it seems to suggest PSUs that can provide a lot more power than what I think should be necessary, resulting in less than optimal power conversion efficiency. It would be nice to see some more objective information. Although, I suppose there is some value in getting something over sized for future proofing. Especially for a quality PSU at less than $100.
  • Egg - Friday, February 28, 2014 - link

    IIRC the Seasonic X650 used to be this price with a modular interface. Well, I guess since the quality is just as good, and possibly even more efficient, we can hope for sales.
  • tynopik - Friday, February 28, 2014 - link

    where's the description of the cable?

    There used to be a chart breaking down each cable and the lengths to each connector:

    also, isn't a shot of the wattage chart de rigeur?
  • extide - Saturday, March 1, 2014 - link

    x2 these should be included
  • Pcgeek21 - Friday, February 28, 2014 - link

    I agree with Daniel; I would be very interested in the performance/efficiency of low wattage power supplies (200W-300W peak output). I run relatively low power servers at home 24/7 such that the 5W delta in power draw can add up over the 4-5 year lifetime of the equipment.

    I purchased an Antec EarthWatts EA-450 ( several months ago for my current server. I would be very interested in determining if it was a worthwhile investment or if there are any better alternatives available on the market.

    I look forward to more PSU reviews.

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