Let's Take a Look Inside

All capacitors in this PSU come from Nippon Chemi-Con, a Japanese company. There are two large main caps and six all solid caps for filtering at the 12V output. Both DC-to-DC VRMs consist of IPD060N03L transistors. They are controlled by an Anpec APW7159 like most VRMs. The transformer, choke, and grey caps in the middle as well as the sister PCB in the upper left corner are part of the resonant switching topology. Seasonic uses ZVS (Zero Voltage Switching) to reduce power loss. With the resonant circuit the manufacturer has no problems with EMC.

Seasonic has implemented a good line filtering stage to help shield the components from EMI in the power grid; it consists of two different coils, some Y-capacitors, and an MOV. In addition, we can find a thermistor and a relay to reduce inrush current. There is also a single X cap with a yellow plastic case. The bridge rectifiers in a GBU case are screwed on one separate heatsink.

The small PCB with an IC for PFC is a little sequeezed between the PFC choke and the first main cap. However, the build quality is still very good, especially the soldering (see the gallery below). The transistors for SR are realized as SMDs, which is why there are three lonely heatsinks beside the all solid caps. Infineon built some of the MOSFETs in this PSU and guarantees a low drain to source resistance in on-state.

Cables and Connectors Voltage Regulation and Quality
Comments Locked

46 Comments

View All Comments

  • jed22281 - Wednesday, March 23, 2011 - link

    ^this!

    JohnnyGuru is where it's at for PSU reviews.
    Badcapt.net is alos a pretty handy resource.
    Anand for SSD's FTW! :-)
  • jed22281 - Wednesday, March 23, 2011 - link

    badcaps.net
  • piroroadkill - Wednesday, March 23, 2011 - link

    Yesss, I do love JonnyGuru for OklahomaWolf's style.
  • jabber - Wednesday, March 23, 2011 - link

    Wouldnt it be better and more reliable to have the main power input lead actually hardwired into the PSU rather than through a connector?

    After all thats the one lead you are going to use.
  • 7Enigma - Wednesday, March 23, 2011 - link

    I was thinking the same thing. Other than the coolness factor of being able to transport just the power brick I don't see a purpose and there is sure to be a minute penalty to efficiency by having those modular.
  • strikeback03 - Wednesday, March 23, 2011 - link

    If they sell different length cables it is nice, for example with the provided 24-pin cable the length is great if you have a bottom-mounted PSU, but it is a lot of extra to hide if you have top-mounted. If they made a shorter cable for top-mounted cases it would be a benefit.
  • somedude1234 - Wednesday, March 23, 2011 - link

    I've done a build with this PSU, and I appreciated the fact that all of the cables were modular during the build process. Not having the bulky main power cables getting in the way until I was ready to route them properly was nice.

    Also, based on the results it doesn't look like the performance is suffering.
  • djc208 - Wednesday, March 23, 2011 - link

    Think I found the PSU for my next upgrade! This or the passive version might be a good idea for my WHS too.
  • Ptaltaica - Wednesday, March 23, 2011 - link

    Great review Martin, but there's one thing I wish you had emphasized a bit more-the significance of that Sanyo Denki fan.

    We all know that most power supplies use cheap, crappy fans; even the ball bearing ones in most units are Chinese-made garbage of questionable quality, and in my experience fan failure is the cause of an awful lot of power supply failures.

    The Sanyo Denki fans Seasonic is using in these units, by contrast, are some of the most reliable, longest-lived and highest quality fans on the market. The impellers are balanced with little blobs of epoxy to minimize wobbling and subsequent wear on the bearings, and they have some of the tightest and lowest-drag bearing assemblies I've ever seen; the only other companies that are in the same quality ballpark are Nidec and EBM-Papst, in my opinion. Delta, Adda and NMB-MAT (aka Panaflo) are decent, but even they're not as good as Sanyo Denki, Nidec or Papst. And everything else is pretty much garbage.

    As far as I can tell, the 9S1212F404 in this PS is a tachless variation of the F401 (datasheet here: http://db.sanyodenki.co.jp/product_db/cooling/dcfa... ). The F401 has a MTBF of 40,000 hours... And that doesn't sound like a lot compared to what some companies advertise. Except that that rating is with a 90% survival rate, and rated at 60*C. Rate it at 25*C or whatever like a lot of companies do and it's probably closer to 160-200,000 hours, if not more.

    Given that it only runs intermittently in the X series power supplies, I can easily see one of these power supplies lasting 10-20 years or longer. There are very, very, very few consumer goods of any kind these days that can legitimately make a claim like that, and-thanks in large part to the SD fans-the X-Series power supplies are the only PSUs I've seen that can.

    i think the relatively small price premium for these units relative to other similarly-sized PSUs is worth it on that fact alone; I've used the X-Series power supplies in every computer I've built at work since they came out, including any of our servers that do not require redundant power supplies, and I'll continue to use them for as long as they'll make them.
  • iamkyle - Wednesday, March 23, 2011 - link

    Once again, no bar charts means no direct comparisons to other PSU's.

Log in

Don't have an account? Sign up now