Performance

Note:
Idle temperatures are recorded with the computer sitting at desktop with no applications open for a minimum of 30 minutes.
Load temperatures are recorded using Prime95. The "In-place large FFTs" test is selected and allowed to run for 30 minutes.
All temperatures are recorded using Core Temp. Since Core Temp acquires its data from the Digital Thermal Sensors on each core of the processor, where it runs hottest, the results are very accurate. More information can be found here.

Fan Noise

At its low setting (PWM controlled), the CNPS 9900 NT is inaudible through the case. You wont be hearing it at all if you have a side panel attached and any other fans within the case. Under hotter conditions, when the PWM sensor increases the fan speed, the CNPS 9900 NT was still relatively quiet. While the cooler was definitely louder than what it was when idling, and did become slightly audible even with a closed case, it still remained quiet, which is good for a 120mm fan.

The problem with PWM fans is that the user can not control the noise as they can with a fan controller (as some prefer to have higher temps but lower noise). I would say this is not a problem with the CNPS 9900 NT as it is not an annoyance at all under full load, and will only but blend in with case/graphics card/power supply fans.

The Intel stock cooler is marginally louder at stock, but a lot louder when under load or when overclocked. The CNPS 9900 NT is noticeably a lot quieter than the Intel stock cooler when running at higher speeds. Having a PWM fan on the CNPS 9900 NT is an extremely smart move by Zalman, because the fan is not noisy and is not frustrating to listen to when running at higher speeds.