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

Results: Silent Pro Platinum 550 W

Efficiency According to the 80 PLUS Specification

Efficiency by Output Power

Cooler Master's Silent Pro Platinum 550 W not only holds its own in our lab tests, but its efficiency even tops the Kingwin Lazer, which just broke Antec's efficiency record two pages ago. At both 20 and 50 percent load, it takes a one-percent lead over the last power supply we benchmarked, achieving 92 and 93 percent efficiency, respectively.

The trend continues at very light loads. No other power supply in this round-up is able to achieve 81 percent efficiency at 25 W. The Cooler Master supply coasts through the other metrics as well, including the tricky ripple and noise test. While the picture on the scope shows slightly larger ripples than Kingwin's exemplary PSU, the Cooler Master product easily complies with the requirements.

A Closer Look at the PCB

The main PCB, colored black, is smaller than the floor area of the enclosure. There is an auxiliary board mounted to a side wall, and massive cooling fins dominate the interior.

When we examined the input filter, along with the primary and secondary side circuits, we couldn’t find any flaws or evidence of cut corners. Cooler Master sources the most important components from suppliers in Japan, using premium parts in a modern circuit topology. The soldering quality is very good here as well (almost perfect, in fact). Not surprisingly, the Silent Pro Platinum 550 W sports a 135 mm fan made by none other than Cooler Master itself.

  • 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.