Testing:

     We talked a lot about how noise is measured on page 1.   Using the same setup described there I tested each of the configurations and recorded the results in both dB and dBA.  Each build was measured first with the side off at idle, then with the side on at idle. 

     Next I put each build under load by running Passmark's BurnIn Test and Futuremark's 3DMark06 simultaneously with the system overclocked to 315 Mhz.  Overclocking was achieved using the Turbo Mode in the ABIT uGuru software for ease of testing.

     In the Stock setup I recorded a peak dB score of 54 dB and 51 dBA with the case open.  The closed case dropped the scores by 2 dB and the dBA scores fell below the 50 dB limit imposed by our budget SLM.  Not a bad start, but I know we can do better!

     To compare each components impact, I installed the HX620 into the stock setup and took these numbers.  (Sorry no pictures survived the 2:00 am configuration change!)  The addition of the Corsair power supply has a very noticeable effect on the overall system noise at every level!  Our peak numbers dropped to 52 dB and a barely there 50 dBA on the Rad Shack meter.

     You have to love a chart like that!  With both the Noctua fans and the HX620 installed our SLM admits defeat!  Turning to my unaided ear for help, I must confess the sound level seems to have dropped by almost half.  If the scientists are to be believed that should indicate a drop in dBA of about 10 dB over stock.

     To make up for our shocking conclusions with all the silent goodies installed, I decided to go the other route and install all of the super-clocking toys used in the CoolIT PCI Cooling Booster Review.

     So here we have the system loaded up with aftermarket fans and goodies.  Now you can see how easy it is to end up with a performance build that sounds like a couple squirrels fighting with hair dryers!  The difference in performance between the build shown here and the silent build may surprise you.  As measured in 3DMark06, the systems both scored within 15 points with the silent build on top.  And during testing the two systems maintained almost identical temperature readings in the uGuru software.

Conclusion:

     The entire cost of the parts used in our silent build was about $245 MSRP ($169.99 for the HX620, $24.99 for the NF-S12-1200 fans, and $18.99 for the NF-R8 fans).  That may sound like a lot but keep in mind you end up with a pretty sweet modular power supply and some good old peace and quiet.  Now you are never going to have a completely silent PC without spending serious money on passive cooling or enclosing the whole PC in some sort of acoustic box but thanks to companies like Noctua and Corsair you can get pretty close without breaking your budget!  Noise dampening components like the grommets used here and full gaskets for your other components could be added to another parts order for just pennies to get things started.

      The Noctua products have shown that the science of fan design really does have a measurable impact on your PC performance and noise level, and their cost is not much more than a good aftermarket fan from a noisy competitor.  I would recommend the HX620 Modular Power supply for anyone looking for a new power supply, the fact that may be the quietest power supply is just a bonus!