Five 550 And 600 W 80 PLUS Platinum Power Supplies, Tested

Results: Kingwin Lazer Platinum 550 W

Efficiency According to the 80 PLUS Specification

Efficiency by Output Power

Up until now, Enermax's Platimax was the the most efficient power supply that we've ever tested. But Kingwin Lazer's tops it. The LZP-550 suffers no weaknesses in the 80 PLUS compliance test and, at 20% load, it’s one percentage point more efficient than the Enermax model. In fact, as power draw drops, Kingwin's advantage over Enermax grows.

At 25 W, the LZP-550's efficiency is a respectable 79 percent, but at 50 W it jumps to 87 percent. This power supply also sports the highest hold-up time in the test field, at almost 30 ms. The ripple and noise values are also excellent. There is simply nothing we dislike about the Kingwin Lazer Platinum 550 W.

A Closer Look at the PCB

The LZP-550's PCB does not cover the entire floor inside the power supply’s enclosure. There is, however, a second circuit board on a side wall.

The input filter can be found on the main PCB and consists of two choke coils, four Y capacitors, and three X capacitors. This PSU does not sport a metal oxide varistor, though. In order to achieve its high efficiency, the Kingwin supply is based on a modern LLC resonant topology. While all the components are high-quality parts from Japan, in our opinion, the soldering quality leaves room for improvement.

  • what? no overload it until it blows test?

    and i was making popcorn.
  • mousseng
    Is that a typo in the first chart for Kingwin's Lazer? It claims that it fails 80 Plus's 50% load spec (82% of 92%); I assume that was meant to say 92% (since that's what the chart below it shows).

    Pleasant read, though, I like PSU reviews.
  • What happen to Seasonic? They have the 520W fanless SS-520FL Platinum version. No PSU test is complete without a seasonic to compare to, in my own opinion.
  • dudewitbow
    jupiter optimus maximusWhat happen to Seasonic? They have the 520W fanless SS-520FL Platinum version. No PSU test is complete without a seasonic to compare to, in my own opinion.they asked for vendors for the PSUs. Theres the offshoot chance that seasonic declined the offer. On other sites, the 520w fanless seasonic unit was compared to Rosewill's 500w silent night unit. The seasonic unit I believe in that review barely edged out a victory.
  • cangelini
    iknowhowtofixitEither the Rosewill FORTRESS was defective or your calibration was off for the last test. Your o-scope shots do not match those of other highly credible reviewers. Also, I'm curious of your testing methodology, but it was not listed.I believe this is still applicable to all of the power supply testing our German team does:,2657.html. I'm waiting for confirmation that I'm right.

    Edit: Yup, that's the correct testing equipment/procedure!
  • Dun dun dun..................... no acoustic performance measured, the only reason some people buy high end PSU's.
  • sebbesapa
    WOW! Thanks a bunch for including the 25watt "Low-Power PC" efficiency test! All other reviewers stop @ 20% load witch is not "idle" or "low load" at all. :-)
  • sanilmahambre
    Power supply unit is where a system builder cannot use a word "BUDGET"
  • jaideep1337
    I don't understand
    Why is the 80 plus spec officially test by having more load on the 3.3v and 5v rails?
    Clearly loading the 12v rail would give us a better overall image
  • jaquith
    Interesting, IMHO the most important aspect is 'Ripple Voltage' @ Rated Load. The only mention I see is a vague reference in your conclusion page.
    Never mind I see the ripple data buried in the individual tests. It would have been better in the summary side-by-side tests.

    Nice article.