Noctua NH-C12P: A Top-Down Cooler Rises Up

Cooling
Viewing page 5 of 7 pages. Previous 1 2 3 4 5 6 7 Next

TEST RESULTS

1) Stock Fan

The fan included with the NH-C12P is the NF-P12. To maximize pressure, the nine fan blades have less curvature than typical fans and there is very little separation between them. This results in more noise, so Noctua implements "vortex-control notches" designed to reduce turbulence and spread the noise generated over a wider frequency range, making for a more pleasant sounding fan. A summary of their claims can be read here.


Brand Noctua Power Rating 0.09A
Model Number NF-P12
Airflow Rating 92,3 m³/h
Bearing Type SSO (Sleeve variant)
RPM Rating 1300
Hub Size 1.61" Noise Rating 19.8 dBA
Frame Size 120 x 120 x 25 mm Header Type 3-pin
Weight 170g Starting Voltage 4.8V

Noctua NF-P12 Measured Data
Voltage
Noise
RPM
12V
32-33 dBA@1m
1330 RPM
9V
22 dBA@1m
1060 RPM
7V
16 dBA@1m
840 RPM
5V
<15 dBA@1m
600 RPM

Fan @ 12V: The fan was fairly loud at 32-33 dBA@1m. It also throbbed with resonant beats. Analysis of the acoustic profile revealed a tonal peak centered at 380Hz. The throbbing, while less aggressive sounding than the normal buzz and whine common to high speed fans, can be just as irritating.

Fan @ 9V: The fan became much quieter, registering only 22 dBA@1m. However, it generated an unusual sound effect — that of an aircraft flying overhead. We interrupted testing twice, believing that a plane was in the vicinity, but it turned out to be the fan itself. We never thought a fan would be capable of producing such a noise, but apparently it hit just the right frequency and tone to create the effect. Spectrum analysis showed tonality around 360Hz with multiple harmonic overtones at lower amplitudes.

Fan @ 7V: The fan was almost silent and very smooth. Close-up it was still audible, and the same airplane-type noise persisted though to a lesser degree.

Fan @ 5V: The fan was effectively silent.


Low-Noise-Adaptor on top, Ultra-Low-Noise-Adaptor on the bottom. Each appears to have an in-line zener diode to drop the voltage to the fan to about 9V and 7V.


2) Cooling Results

The NH-C12P showed itself to be an exceptional performer with the stock Noctua NF-P12 fan. While unpleasantly loud at 12V, setting the fan to 9V provided almost equal performance but with less than half the subjective noise. At either voltage the thermal rise was well below 20°C, which is superb. 7V is probably the best trade-off between noise and performance. At 16 dBA it is unlikely to be audible in most environments, and the 20°C temperature rise is excellent. Going to 5V provided very little acoustic benefit and resulted in an additional 5°C increase in temperature.

Noctua NH-C12P w/ stock fan
Fan Voltage
Noise @1m
Temp
°C Rise
°C/W
12V
32-33 dBA
37°C
16
0.21
9V
22 dBA
38°C
17
0.22
7V
16 dBA
41°C
20
0.26
5V
<15 dBA
46°C
25
0.32
Load Temp: CPUBurn for ~10 mins.
°C Rise: Temperature rise above ambient (21°C) at load.
°C/W: based on the amount of heat dissipated by the CPU (measured 78W); lower is better.



Previous 1 2 3 4 5 6 7 Next

Cooling - Article Index
Help support this site, buy the Noctua NH-C12P CPU Cooler from one of our affiliate retailers!