The Test System and Thermal Results
Testing for the CPU coolers is done with the use of RealTemp to ascertain temperatures, Intel Burn Test to deliver the load to the CPU and CPU-Z to verify the CPU speed and the voltage being used in Windows. All of the testing is done with an ambient temperature of 24.5-25°C and humidity is maintained to 35% sometimes less.
For the "stock" runs, it's more of a plug and play setup where the PWM of the motherboard is in control of the fans speeds for both the idle and load results. Speed Step is active and the processor idles at 1600 MHz and loads at 3500 MHz for the stock settings. I also set the memory to run at 1600 MHz for stock. As for the overclocked runs, I load the CPU at 4.5 GHz and idle results are obtained with 7.5V to the fans while the load run is set to deliver 12V to the fans. This allows me to gauge the lowest and highest fan ratings for my charts.
Things don't start off for the CNPS9900DF that well. The stock and overclocked results are acceptable, but it doesn't keep up with the other dual tower cooler designs. At stock clocks I got a 28 degree reading, and with just slightly more voltage, with the overclock idling, it jumped two degrees.
The load results for the stock runs were really quite good at 51 degrees. Once the overclock was applied the results jumped 25 degrees to 76 degrees. It's not that great of a showing and puts the CNPS9900DF in the bottom ten coolers I have tested like this.