Noctua NH-D14 flagship dual-fan CPU cooler

Cooling
Viewing page 5 of 9 pages. Previous 1 2 3 4 5 6 7 8 9 Next

FAN TEST RESULTS

We've seen the 12cm NF-P12 before, on the Noctua NH-U12P. The 14cm NF-P14 is new to us. It is similar in design to the NF-P12, except for size: To maximize pressure, the nine fan blades have less curvature than typical fans. There is more of a gap between the blades than in the 12cm model. The "vortex-control notches," which apparently reduce turbulence and spread the noise generated from the interaction between the strust and the fan blades over a wider frequency range, making for a more pleasant sounding fan. The 14cm fan's frame is fairly minimal, allowing for the same hole mounting pattern as a standard 12cm fan. Both fans have good strut geometry; the trailing edges of the blades intersect with the struts almost perpendicularly, which in theory also helps to minimize tonal aspect of the turbulence noise. Noctua's "self-stabilising oil-pressure" bearing (SSO bearing) is said to surpass ball, sleeve or liquid bearings in terms of long-term stability and quietness. More details of the fan designs can be read on Noctua's web site.

The 14cm fan bearing looks a bit different from the 12cm fan. The bearing end looks similar to that of the excellent Sanyo Denki San Ace fan employed in the high end Seasonic X series and MD12 series power supplies. (See photos on this page.) Noctua has this to say: "Both the impeller hub and the bearing shell of the NF-P14 are metal reinforced in order to achieve ultimate manufacturing precision, high durability and vibration-free running."


The metal end of the fan shaft looks impressive..

The blue marked parameters in the tables below were measured in our lab. Both fans draw exceptionally low power.

Brand Noctua Power Rating 0.09A
Model Number NF-P12
Airflow Rating 92,3 m³/h
Bearing Type SSO
RPM Rating 1300
Hub Size 39.5 mm Noise Rating 19.8 dBA
Frame Size 120x120x25 mm Header Type 3-pin
Weight 170g Starting Voltage 4.8V

Brand Noctua Power Rating 0.10A
Model Number NF-P14
Airflow Rating 110,3 m³/h
Bearing Type SSO
RPM Rating 1300
Hub Size 39.5 mm Noise Rating 19.8 dBA
Frame Size 140x140x25 mm Header Type 3-pin
Weight 150g Starting Voltage 6.5V

Two low noise adapters are provided, one for each of the fans. The instruction sheet warns against running both fans off either adapter simultaneously. This can be done with the splitter cable that's also provided.


Ultra-Low-Noise Adaptors: The blue one has an 81 ohm resistor, while the black one measures 50 ohms. The first brings the speed of the 12cm fan down to ~900, and the second does the same to the 14cm fan.

To get started with the acoustics, noise and speed tests were run on each fan. Each fan was left mounted on the heatsink (with the other one removed) since that's the way they would be used. The noise of both fans running together was also measured; this is the way the heatsink is meant to be used. Note the order of the columns in the table below: All the Sound Pressure Level (SPL, measured in dBA at 1m distance) data is in the middle three columns for ease of comparison.

Noctua NH-D14 Cooler: Fan Test Results
NF-P14 fan
SPL, both fans
NF-P12 fan
V
RPM
SPL
SPL
RPM
V
12V
1230
30
30
24
1285
12V
11V
1130
28
28
22
1210
11V
10V
1040
25
26
20
1100
10V
9V
940
22
22
17
1000
9V
8V
840
19
20
16
900
8V
7V
720
15
16
13
800
7V
6.5V*
660
14
14.5
12
680
6V
5V
490
12
12
11
570
5V
* 6.5V is the min. start voltage of NH-P14 fan; to get it to run at 5V, the fan must be started at a higher speed, then the voltage reduced.

Our SPL measurements make a mockery of Noctua's claimed 19.8 dBA at full speed (as well as the ~13 dBA claim with the ULNA). This exaggeration is especially notable when the rest of the specs are so professionally correct.

The 14cm fan is considerably louder than the 12cm model throughout the speed range. The difference reduces as speed is reduced; by 7V, the noise level from either fan is soft and gentle enough that the 2 dBA@1m difference is of little importance.

Each fan has a better qualitative sound when run by itself. Both fans are fairly smooth, but with a bit of growl and some tonality that becomes more clearly audible as turbulence noise subsides with reduced voltage. The 14cm fan seemed a bit smoother in this regard; despite its higher SPL, it somehow made a more pleasant sound through much of the speed range.

Run together, the sound has more growl and turbulence, and there are some mild intermodulation effects between the fans, which is almost unavoidable due to their slightly different speed. At 7V, the overall SPL of the two fans together matches the reference Nexus 120 fan at 12V. We prefer theNexus for its smoother, less tonal sound.

At the 6.5V minimum voltage determined by the larger fan, the two fans are very quiet together. There is considerably less tonality than at 7V.

When the low noise adapters are used as directed by Noctua, the end result is about 22 dBA@1m, with each fan spinning around 900rpm.



Previous 1 2 3 4 5 6 7 8 9 Next

Cooling - Article Index
Help support this site, buy from one of our affiliate retailers!
Search: