Temperatures, Fan Speed, and Acoustics


The high efficiency means that this power supply needs to dissipate less heat, which is icing on the cake. The temperatures on both heatsinks are so low that you could practically run this PSU fanless. Once we hit 100% load, temperatures start to increase, but we don't expect very many users to come anywhere near that point. What's interesting is that fan speed begins to ramp up faster than temperatures, and in fact the temperature graphs drop between the 80% and 100% load marks. Still, better safe than sorry. As for the exhaust temperature, it's very close to the heatsink temperatures, so the heatsinks and fan are doing a good job of getting heat out of the power supply.


As we saw in the temperature graph, fan speed begins to ramp up at around a 500W/50% load. It spins at 750 RPM up until the 50% mark, at which point fan speed ramps up linearly until the maximum 1500-1600 RPM at 100% load.


Noise levels for the first half of the graph are extremely low, but unfortunately noise increases rapidly with fan speed beyond that point. This is a real pity, since the heatsinks aren't even that hot and it certainly would be possible to run the fan at a lower speed. The starting point of 18dB(A) is not something you will even notice, and we couldn't hear any ticking noises either (something we have seen in non-PWM controlled fans). However, the final output of 29dB(A) definitely doesn't qualify as being silent. The good news is that you can use this power supply up to a load of around 800W and still have an acceptable amount of noise, which is sufficient for even triple SLI systems -- and those will create plenty of noise just from the graphics cards. Truthfully, for a unit delivering over 1100W of power, 29dB(A) is not at all something we would call a poor result.

Efficiency and PFC Conclusion
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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.

    http://www.anandtech.com/casecoolingpsus/showdoc.a...">http://www.anandtech.com/casecoolingpsus/showdoc.a...

    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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