The frame is comprised of Noctua’s usual glass fiber reinforced PBT plastic, and all the mounts/corner guards are brown silicone rubber. The build quality is the usual Noctua top notch. There’s no wobble or slop on the impeller, the shroud and impeller are both uniform in their castings, and it feels solidly built.

Noise and Cooling Benchmarks

To test the fan against it’s big brother the NF-A14, we’ll be using my airflow-focused PC as a test bench. I’ll be testing 2-A14s vs 3-A12s, with both a “Silent” fan curve and a 100% speed fan setting using the included low noise adapters. This combination should give us an idea if we can been cool + quiet. I’ll also test a 5th setup where the CPU fan profile is also set to “Silent” instead of our control 60% fan speed to see if we can eek out any more silence.

AMD Ryzen 1600 overclocked to 3.8Ghz

Asus PRIME X370-PRO Motherboard

EVGA SuperSC 16GB (2 x 8GB) DDR4–3200 Memory @ 2933 speed

Samsung 850 EVO 500 GB SSD

MSI GeForce GTX 1070 GAMING X 8G

SeaSonic PRIME Titanium 750W PSU in Hybrid Mode

Fractal Design Meshify C Case

Thermalright Le Grande Macho RT CPU Cooler

2 x Noctua NF-A14 PWM fans

3 x Noctua NF-A12x25 PWM fans

Measurements & Methodology

We will be measuring Noise and Temperature readings for each setup iteration. To generate as much load and heat as possible, IntelBurnTest (IBT) and Heaven Benchmark 4.0 (HB) will be run in tandem. IBT will run a Standard Stress Test utilizing all cores/threads, and HB will run a benchmark at Ultra Quality, Extreme Tessellation, 8x Anti-aliasing, and at 1920x1080 windowed resolution.

Noise

Noise will be measured using the Niosh Sound Level Meter App for iPhone, which is a free calibrated app for collecting A-weighted noise measurements. It will be measured while idle, and near the end of the testing cycle at two locations:

1 meter directly in front of the case intakes. 1 meter diagonal to the front/left/top vertex corner of the case, which tends to be where my head is while sitting in a chair with the case on the floor under the desk.

The environment will be as controlled as possible, with HVAC, refrigerators, and other noise generating sources turned off during readings. Tests are run during quiet times, which resulted in an approximately 27.1 dB background noise level.

Temperature

Temperature readings will be collected using HWiNFO, and logged to CSV for analysis.

The environment will be as controlled as possible, with HVAC keeping the room steady at a 22°C base temperature, and only temporarily shutoff at the beginning and the end of tests to measure noise levels.

Fan Curve Settings

To limit the number of variables to test, the CPU fan will be set to a constant 60% RPM. When isolated, this results in a 27.8 dB(A) measurement at 1 meter from the front of the case and is slightly discernible when listening carefully with an ear pointed towards the case. At head level the CPU fan noise is not audibly discernible or measurable.

For the “Silent” fan curve mentioned above, I used ASUS’s standard “Silent” fan profile, which has the following curve points: 20% @ 20°C, 70% @ 70°C, 100% @ 75°C.

Q: Why are you comparing 2 fans to 3?

Because we are doing whole system testing. 2–140/3–120 is becoming a common fan layout in cases, so it makes sense to compare how other people would setup their cases to maximize airflow. From the fan’s spec sheets, a single A14 can generate 115.5 m³/h airflow with the L.N.A, while an individual A12x25 can generate 84.5 m³/h with it’s L.N.A. An apples to apples comparison would result in a 36% difference in airflow, whereas 2 vs 3 results in a 9% difference. (2*115.5) = 231 ≈ 253.5 = (3*84.5).

Results

From the data below, we can see that the setups are very close in cooling performance, but the 3 NF-A12x25’s do have a few degree edge over their 140mm brothers. Setting either fan setup to 100% speed does increase the cooling power, but the silent fan profiles seem to cool the system adequately with max temps in the 70–75°C range for CPU and GPU.