Voltage Regulation

+3.3V Regulation/Ripple and Noise
Load Voltage
5% +0.91% (14mV)
10% +0.91% (22mV)
20% +0.30% (26mV)
50% -0.61% (32mV)
80% -1.82% (14mV)
100% -3.33% (39mV)
110% -3.63% (42mV)
Crossload +12V max. +0.00%
Crossload +3.3V/+5V max. -0.30%


+5V Regulation/Ripple and Noise
Load Voltage
5% +1.20% (10mV)
10% +1.00% (17mV)
20% +0.80% (20mV)
50% -0.40% (20mV)
80% -1.40% (25mV)
100% -2.40% (28mV)
110% -2.60% (30mV)
Crossload +12V max. +0.60%
Crossload +3.3V/+5V max. -0.40%


+12V Regulation (Worst Rail)/Ripple and Noise (Worst Rail)
Load Voltage
5% +1.92% (18mV)
10% +1.92% (34mV)
20% +1.83% (38mV)
50% +1.50% (51mV)
80% +1.25% (64mV)
100% +1.08% (67mV)
110% +0.83% (67mV)
Crossload +12V max. +1.08%
Crossload +3.3V/+5V max. +0.83%

Noise Levels

Acoustic Noise Impressions
Load Opinion
5% low fan noise
10% low fan noise
20% low fan noise
50% low fan noise
80% low fan noise
100% fan noise
110% fan noise

Efficiency and PFC

115VAC. 60Hz
Load Efficiency PFC
5% 77.53% 0.799
10% 86.93% 0.872
20% 88.79% 0.927
50% 92.20% 0.965
80% 91.46% 0.975
100% 89.09% 0.979
110% 88.71% 0.981

At 10% load the power supply reaches a higher efficiency than many power supplies reach at their optimal output. With a starting value of just under 0.8 that quickly scales into the >0.92 range, the power factor is relatively high as well. More than 92% efficiency can be achieved during 50% load, which is an awesome result. Moreover the PSU doesn't mind the crossload tests with different loads on the outputs; the voltage is always within ATX specification. Nevertheless the voltage on the 3.3V output could be higher while ripple and noise should be much lower on this output since this is a high-quality product.

As far as acoustics are concerned, the fan is almost always near-silent. It's only at 100% load that the fan becomes noticeable, but considering the 750W power output you would likely have several other components generating more noise to even reach that level (e.g. CPU and GPU fans).

Overall, the performance of the Platimax 750W is very good—just as we'd expect from a halo product. What's a bit surprising, however, is that our test sample technicallly failed to achieve the required 90% efficiency at 20% load for 80 Plus Platinum certification. Of course, there are differences in test environments and that may be the reason we "only" managed 89% efficiency instead of 90% efficiency. Since we're not the people doing the actual certification, we'll leave it there.

Switching Circuits and Components Conclusion


View All Comments

  • colonelciller - Friday, February 10, 2012 - link

    call me a newb... but why would I want a power supply such as this?

    honest question. Won't other computer components will be designed around more standard power supply output characteristics anyway?
  • wifiwolf - Friday, February 10, 2012 - link

    PSU is one of the most important components.
    You don't want PSU to fail on you ever.
    It starts with spiky stability and in time components start failing and you never relate it directly to power supply until you monitor those voltages.
    Probably everyone looking at this article gone through that until they wised up.
    When you just use Word and Excel on your computer, you probably survive with system hanging once a month in a stable environment. But when you push a bit harder on your system, sometimes the result can be a computer burning literally.
  • medi01 - Sunday, February 12, 2012 - link

    Except that more efficient PSU that race for higher numbers tend to be much more complex, which definitely does NOT help with reliability. (at least as far as my personal experience with Enermax Modu 82+ goes, broke within first 2 month, occasional to frequent reboots 2 years later =/) Reply
  • Iketh - Friday, February 10, 2012 - link


    what wifiwolf said are the main reasons, but high quality power supplies also lower power bills considerably on high-watt systems (crossfire/sli/overclocking etc...)

    the 2 rules of thumb when building your own system is 1) don't skimp on powersupply 2) don't skimp on motherboard. You can skimp on CPU/RAM and everything else because you can make adjustments on those components so that they work, as in megahertz or RAM timings and the voltages to those components, but you can't adjust how capacitors on motherboards and powersupplies deliver said power.

    you have to experience the headaches associated with cheap power supplies before you completely understand.
  • bji - Saturday, February 11, 2012 - link

    False dilemma.

    The choice is not only between this power supply and "cheap power supplies".

    There are also power supplies at 1/2 the cost of this one that would likely have performance and reliability that would be so similar as to, for most people, be indistinguishable.

    Therefore the question of, why would this power supply be a better choice than a good quality power supply that is much less expensive, is a valid question and not one that should be so easily dismissed.

    I paid something like $130 for a Seasonic 650 Watt gold power supply and I am not sure what I'd really be getting with this Enermax supply that is tangibly different.
  • bji - Saturday, February 11, 2012 - link

    Just checked my newegg order history; I actually paid $120 with free shipping in October 2010 for a Seasonic X650 Gold. It is 1% - 2% less efficient than this Enermax.

    Let me reiterate that I think it's valid to question the value of this power supply rather than dismissing the question outright.
  • Iketh - Saturday, February 11, 2012 - link

    Well I should have mentioned that I'm not endorcing this power supply whatsoever, just answering his question about "standard" vs good.

    Minimum quality I use in my own systems is Antec 80-plus bronze.
  • beginner99 - Saturday, February 11, 2012 - link

    I good power supply is of course important but its like with CPUs. The top notch model i overpriced compared to what it offers. So yeah, a 120$ Seasonic Gold sure is better value for most people assuming they last the same time (that's the big question as a power supply usually is re-used for the next build). Reply
  • cfaalm - Saturday, February 11, 2012 - link

    I guess it's still like what wifiwolf said still. It depends on how hard you think you're going to drive your system. Hardly any of the manufacturers like Asus, Dell or Acer are going to bother with these PSUs. They can settle for anything that goes up to 75% efficiency on 50% load. If you build your own just for fun but still don't drive it very hard, you'll be OK with a "standard" PSU.

    For everyone else, serious OCing, gaming, heavy duty video and audio etc. you don't want to skimp on the PSU as you know you'll be asking for the last drop of CPU/GPU power your system can muster.
  • just4U - Sunday, February 12, 2012 - link

    I think the days of the cheap PSU (save maybe for OEMs) is gone. Even $50 power supplies are fairly decent these days. Reply

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