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 24.5-25C 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.
As we start things off with the idle thermal results, you can see that with the fan adapter in play, at stock the T40 comes in respectively with a 27 degree reading. Once I let the fans go to full speed, I was able to remove a degree even with the overclock applied and a bit of extra voltage going through the CPU.
Any way you want to cover the loaded results, they just aren't good. With only one fan on the T40 it allowed my CPU to reach 84 degrees when overclocked, and even at stock settings is was 55 degrees.
Adding the second fan from the T20 I was able to take off an additional three degrees at stock levels, and had that same three degree improvement when I overclocked the processor. At this point I am still left scratching my head as to why NZXT classifies these as "performance" coolers.