So far things have been pretty typical for a power supply review. After all, there are only so many ways to design a standard PSU chassis and provide cable harnesses. Now we come to the interesting part: the internals. Enermax did a tremendous job designing this power supply, but let's start at the beginning.

When I first saw the filtering stage, I asked the representatives at Enermax if CWT is the ODM. They responded by threatening to beat me up. ;-) Anyway, the filtering stage looks very good and has all of the necessary components. The coil sits on top of the PCB, covered with shrinking hose -- hence the similarity to CWT PSUs. Right nearby are the rectifier bridges, both without heatsinks. The PFC stage follows next and the coil is placed on a solid socket. Matsushita builds the three primary capacitors, rated for 220µF and 400V at 85°C.

Enermax is particularly proud of their transformers, since they synchronized both of them for quad forward circuitry. Two synchronized transformers will share the work equally, which makes the work more efficient. The power supply also features eight safety features such as OCP (Over Current Protection), UVP (Under Voltage Protection) for the AC part, UVP (Under Voltage Protection) for the DC part, OPP (Over Power Protection), OTP (Over Temperature Protection), SIP (Surge & Inrush Protection), and SCP (Short Circuit Protection).

This power supply uses a DC-to-DC topology, which means that the 3.3V and 5V rails do not come directly from the transformer anymore. The transformers can now be built for the sole purpose of delivering a stable 12V output. In DC-to-DC designs, so far the extra circuitry has been included on the main PCB in the secondary stage of the PSU. Enermax relocated this functionality to a sister PCB that we will describe in the next paragraph. The secondary stage in this power supply now only has to deal with the six 12V rails. The capacitors for this purpose are all made by Chemi-Con, one of the best but still affordable Japanese capacitor manufacturers.

So where are the 3.3V and 5V rails created? Let's have a look at the large sister PCB where the cable management sockets are located. The left side is where it happens. The upper part is for the 5V output and the bottom is for 3.3V. The output feeds directly into the cable harnesses, and from there on to the peripherals. Since this is done totally independent from the other 12V rails, this power supply can output 99% of its rated power on just the 12V rails, which we will verify in a moment. Other power supplies that generate the 5V and 3.3V rails from the transformer normally have problems with the voltage distribution if not loaded according to ATX-norm.

Cables and Connectors Testing with the Chroma ATE Programmable Load
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  • strikeback03 - Friday, November 7, 2008 - link

    You should have stated you were using a 700W power supply, your post indicated you thought you were drawing 700W.">

    I have a similar system on my desk here at work (only 3 GHz on the q6600, but it is a B3 stepping; 2 HDD, 1 optical, 7300GT instead 0f 9800GX2) and idle is about 100 W at the wall, peak draw is like 160-170. Your system probably draws another 120-150W at idle, and maybe 250 at full power. A 700W power supply is quite reasonable for that system, as it probably uses 200-250 at idle and another 150-200 at full bore. It won't draw 700W.
  • Freddo - Thursday, November 6, 2008 - link

    This PSU is so cool, as it's very energy efficient & have modular cables.

    I would really like to see a PSU as energy efficient as this one, but down at ~400W or so instead, and with passive cooling, or at least "half passive", with a small 80mm fan outwards that only starts to spin when it's near full load and getting hot.

  • Christoph Katzer - Thursday, November 6, 2008 - link

    Wait until next year's ~CES/CeBIT, there is a manufacturer who might have exactly what you're waiting for...
  • iwodo - Thursday, November 6, 2008 - link

    As Anand as well as other tech site has confirm, even with GTX SLI and Quad Core CPU, you will hardly need more then 500W, lets give it a peak spike of 40% will only means 700W.

    So why are we having PSU that starts at 800W? When only less then 5% of market uses it. Not to mention 1000W PSU.
  • Shmak - Thursday, November 6, 2008 - link

    All power supplies reach their efficiency peak at about 50% load, which is shown on any psu review you care to look at. Therefore, if your system idles at around 500W, a 1000W psu will likely be most efficient for your build.
  • GaryJohnson - Thursday, November 6, 2008 - link

    Watts don't mean anything. What matters is having enough stable amps on a couple (or single) 12v rails to power SLI or Crossfire.
  • OddJensen - Thursday, November 6, 2008 - link

    Try a Core i7 w/HD4870X2 in crossfire. You'll soon find out why we have 1kW PSUs.
  • larson0699 - Thursday, November 6, 2008 - link

    How about a Pentium D or Skulltrail with quad GTX 280's?

    Do like the small jets and shut off everything else before powering up THOSE engines.
  • Nigel.k.l - Tuesday, November 26, 2019 - link

    I purchased mine back in 09 and its still running, I7 8700k 1070ti system

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