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Seasonic S12G 450 W

Four 80 PLUS Gold Power Supplies Under 450 W, Reviewed
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In past round-ups, Seasonic fared well with its X family of power supplies. They're notably fully modular and equipped with dynamic fan control. Additionally, the company is known for its fantastic build and component quality.

But for this story, Seasonic sent us the 450 W version of its S12G. For a price right around $75, you get a compact, 80 PLUS Gold-certified PSU with completely fixed cabling. That makes the S12G the only power supply in our round-up without cable management. In return, a combination of sleeved, round cables and flat cables turn out to be the long side, giving you plenty of room for routing. Moreover, you get two auxiliary PCIe connectors and eight for SATA-based drives.

Surprisingly, Seasonic's build quality doesn't quite match up to the competition. Similarities we do find are a single +12 V rail rated for up to 37 A and five-year warranty coverage.

AC Input100-240 V, 50-60 Hz
DC Output+3.3 V+ 5 V+12 V (#1)+12 V (#2)+12 V (#3)+12 V (#4)-12 V+5 Vsb
20 A20 A37 An/an/an/a0.3 A2.5 A
Individual Output  32 A  3.6 W12.5 W
Rail UtilizationSysSysCPU & VGA
Combined Output100 W444 W
Total Continuous Output450 W
Peak Outputn/a

Seasonic’s X line is typically a top contender in our performance measurements. The less-expensive S12G still has something to prove, though. It does master our efficiency testing, according to the 80 PLUS specification, and even has a bit of room to spare.

At very low loads, the S12G’s efficiency is about the same as Corsair's RM450. At 25 W, it tails Cooler Master's V450S by about 10 percent. But in standby, without any load, Seasonic has the only PSU able to compete with the RM450 by demonstrating .05 W of consumption.

For those of you keeping score at home, that means this PSU hasn't exhibited any real weaknesses yet. The ripple and noise measurements continue along the same lines. There’s barely any ripple, and the curve is pretty smooth.

Thanks to its hybrid cooling solution, Corsair's RM450 just can’t be beaten when it comes to acoustics. Seasonic often triumphs in this metric. However, the company chooses not to use the dynamic cooling we've come to appreciate from its X family. That doesn't mean the S12G is loud. Quite the opposite. It's fan is on the quiet side, registering between 30.9 and 31.3 dB(A).

A Look at the PCB

There's no cable management, no hybrid fan control, and Seasonic sneaks in with the lowest price in today's story. Did the company have to cut some corners when it was picking components and putting the S12G together? Nope. We find a DC-to-DC converter topology with LLC, as well as a very good input filter including two X and six Y capacitors, three choke coils, and a MOV.

Hitachi supplies the primary capacitor. On the secondary side, there are a number of capacitors from the South Korean manufacturer Enesol, as well as a few by Chemi-Con and Rubycon. All in all, the parts are higher-quality than what we found from the other power supplies in our round-up. And then there’s the immaculate soldering work.

The bottom line is that Seasonic does everything right for a PSU in this price category for both component selection and build quality.

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Top Comments
  • 16 Hide
    oczdude8 , July 15, 2014 8:47 AM
    Is it just me or is $100 WAY too much for a 450W psu......
Other Comments
  • 7 Hide
    iknowhowtofixit , July 15, 2014 1:13 AM
    No ripple tests, no noise (not sound) tests, and no oscope shots.... *facepalm*

    Readers have been begging for you guys to do a proper PSU test for years. I'm glad to know Tom's has taken the time to listen.

    /sarcasm
  • 3 Hide
    iam2thecrowe , July 15, 2014 1:39 AM
    they did ripple tests......they load tested them....... that's about as much as most readers need to know, that it wont blow up at 100% load and wont damage components with excess ripple. better than some reviews i have read "we hooked it up to a pc and it worked, give gold award..."
  • 3 Hide
    Onus , July 15, 2014 5:56 AM
    Too bad Rosewill did not submit its Capstone for this roundup.

    It would have also been nice to see one of Seasonic's TFX units included.
  • 6 Hide
    iknowhowtofixit , July 15, 2014 7:22 AM
    Quote:
    they did ripple tests......they load tested them....... that's about as much as most readers need to know, that it wont blow up at 100% load and wont damage components with excess ripple. better than some reviews i have read "we hooked it up to a pc and it worked, give gold award..."


    I lol'd at the operational noise graph because it tells you nothing. What rail(s) are they testing? Who knows? Who cares...

    You are welcome to continue to defend the article, but the truth is that nobody takes a Tom's Hardware PSU review seriously. This review doesn't do anything to change that perception. Compared to the depth of analysis that goes into other PC components, it is disappointing to see Tom's continue to ignore the requests of its readers to bring a thorough, full-featured PSU review to the table.

  • 3 Hide
    xenol , July 15, 2014 8:09 AM
    Ripple and line noise tests are the indicators of whether or not a power supply is made with solid parts or made with parts that just do the job and will probably last about a year of nominal use before releasing the magic smoke. If there's a lot of ripple, then the motherboard's house keeping circuitry is going to do a lot of work to keep stable voltages (especially when a difference of even 0.1V matters).

    Yes, these are supposedly made by top-tier manufacturers, but just because they have a reputation in the past doesn't mean they have a clean slate the entire way through.
  • 6 Hide
    2Be_or_Not2Be , July 15, 2014 8:46 AM
    I am just happy that we have some reviews of more reasonable P/S. Most people I know aren't running 1000W+.

    "In order to keep prices within reason, we settled on an 80 PLUS Gold rating as sufficient to meet our second demand."

    I'm also happy with my 80+ Bronze P/S. Frankly, when you're buying smaller output P/S, I really don't know why anyone would need to get a Gold-rated one.
  • 16 Hide
    oczdude8 , July 15, 2014 8:47 AM
    Is it just me or is $100 WAY too much for a 450W psu......
  • 3 Hide
    Adroid , July 15, 2014 11:53 AM
    Yea I am really confused by the huge price tags here.

    I paid like 70$ for a top of the line 660W seasonic platinum PSU after MIR. Needless to say I was patient and waited for a good deal, but I see high quality 650-750W PSUs for 80$ after MIRs regularly.
  • 0 Hide
    hannibal , July 15, 2014 11:59 AM
    Well good quality 400W PSU can be better choice than good quality 600W version. If it works within its best efficiency area.
  • 0 Hide
    Adroid , July 15, 2014 12:06 PM
    Quote:
    Well good quality 400W PSU can be better choice than good quality 600W version. If it works within its best efficiency area.


    True, PSUs typically operate most effeciently at 80% load. I build gaming rigs though, so 400W is always too small.

    I just expected smaller PSUs to be cheaper, that's all.
  • 5 Hide
    Drejeck , July 15, 2014 12:21 PM
    There's a big mistake in considering 400W insufficient for gaming. I have a 770 phantom, a 750ti from kfa2 for physx, an i7 2600K at 4,4ghz, various neons, a load of fans, 4 SSDs, 2 black faex 2TB, an asus xonar d2x, and still I can't reach over 420W of power consumption in torture tests, measured with the highest end APC Smart (865W UPS). I have a Corsair 850W Gold, which is a Seasonic rebrand. And I'm ashamed I went so much overkill with my PSU.
    This review feels like useless. There's no ripple testing, whatever the second comment user says. Get some review from Guru3D and you'll see.
    Based on words I can't compare with other products on other reviews, so this is quite a fail.
  • 0 Hide
    Drejeck , July 15, 2014 12:23 PM
    Oh I forgot, I'm building a gaming rig with a PicoPSU 160XT... deal with it
  • 0 Hide
    Adroid , July 15, 2014 12:43 PM
    Quote:
    Oh I forgot, I'm building a gaming rig with a PicoPSU 160XT... deal with it


    Haha... well I can beat you on your own games from my cell phone.
  • 4 Hide
    logainofhades , July 15, 2014 12:45 PM
    Quote:
    Is it just me or is $100 WAY too much for a 450W psu......


    I agree. If I am buying a gold rated 450w unit, I am not buying any of these. I will go and get a Capstone 450w for $60.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16817182066
  • 0 Hide
    Drejeck , July 15, 2014 12:59 PM
    Quote:
    Quote:
    Oh I forgot, I'm building a gaming rig with a PicoPSU 160XT... deal with it


    Haha... well I can beat you on your own games from my cell phone.

    Hahahaha yup, given a micro HDMI port. But I'm speaking of a machine capable of challenging the PS4. My old NES 8 bit is going to be revived with the KFA2 750Ti and an i5S processor. Actually I badly wanted the Broadwell architecture but I can't wait 2015...
  • 4 Hide
    Onus , July 15, 2014 1:31 PM
    I used an i5-3570K and an overclocked HD7970 to mine last year, and it pulled 312W from its UPS. Under a gaming load, the GPU usage would drop, and the CPU usage would be higher, but I'd be surprised if it needed more than 350W-375W. It happened to have a pair of WD Blacks in a RAID1 also, plus a SSD, but no other bling. A 400W PSU is plenty for a competent gamer.
  • 4 Hide
    damric , July 15, 2014 2:23 PM
    This is not a Power Supply Review, this is an informercial.

    The three most important things to review on a power supply are regulation, ripple suppression, and hot box stability.

    My suggestion for Patrick is to go look at CRMARIS and Oklahoma Wolf's PSU reviews to see how a real review is done.

    The only way to verify true quality is with hot box torture. That's how you separate the elite PSUs from the turds wrapped in a box.

  • 0 Hide
    lp231 , July 15, 2014 2:28 PM
    Who the heck wants to spend that much on a 450w PSU? With that amount you can get a PSU with a lot more wattage and still have a 80 Plus Gold rating.
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817139056


  • 0 Hide
    damric , July 15, 2014 2:48 PM
    The $90 750W SUPERNOVA G2/Superflower Leadex sets the bar for quality PSUs. If your PSU you costs more than that and is less wattage then it is fail.
  • 0 Hide
    lp231 , July 15, 2014 3:02 PM
    Quote:
    The $90 750W SUPERNOVA G2/Superflower Leadex sets the bar for quality PSUs. If your PSU you costs more than that and is less wattage then it is fail.


    Unless they buy it for the rating and know nothing else about a PSU, but if you checked out the price links to Amazon, no one is that dumb to spend that much on a small wattage PSU. The CM one is sold by some unknown vender with a $44 dollar shipping! Corsair has some reviews, but that's not for the 450w, they're reviews for higher wattage models.
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