Four 80 PLUS Gold Power Supplies Under 450 W, Reviewed

Seasonic S12G 450 W

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.

Swipe to scroll horizontally
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 OutputRow 2 - Cell 1 Row 2 - Cell 2 32 ARow 2 - Cell 4 Row 2 - Cell 5 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.

  • iam2thecrowe
    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..."
  • Onus
    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.
  • xenol
    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.
  • 2Be_or_Not2Be
    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.
  • oczdude8
    Is it just me or is $100 WAY too much for a 450W psu......
  • Adroid
    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.
  • hannibal
    Well good quality 400W PSU can be better choice than good quality 600W version. If it works within its best efficiency area.
  • Adroid
    13725552 said:
    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.
  • Drejeck
    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.
  • Drejeck
    Oh I forgot, I'm building a gaming rig with a PicoPSU 160XT... deal with it