PC fan makers publish more noise data than any appliance brand we have covered. Nearly every model carries a dB(A) figure, tied to a stated maximum RPM, and several brands publish a second figure for the fan running slower. Compared with a freezer maker that prints one number for three cabinet sizes, this is luxury.
We read the spec sheets and infosheets for eighteen fans from nine brands, covering both 120mm and 140mm, and both case airflow and radiator use. The figures run from 9.8 dBA to 39.7. Here is how to read them.
Our 7 picks are listed above, with full specifications for each.
Two things are true of almost every number in this category.
It describes full speed. be quiet! labels its figures "at 100% PWM / 12V". Noctua gives the maximum. Corsair publishes a range across its whole speed range, 10 to 36 dBA, which is the most honest presentation here.
It describes a bare fan in open air. Nobody publishes a figure for a fan bolted to a radiator or sitting behind a dust filter, and nobody names a test standard such as ISO 7779.
So two figures are only comparable at similar RPM. The Silent Wings 4 140mm at 13.6 dB(A) spins at 1100 rpm. Noctua's NF-A12x25 at 22.6 dB(A) spins at 2000 RPM and moves air through much more resistance. They are not 9 dB apart in any real build.
For the wider problem, see why you cannot compare dB ratings across brands.
Speed is the whole story
The best evidence comes from makers publishing two figures for one fan.
- Noctua NF-S12A: 17.8 dB(A) at 1200 RPM, 10.7 dB(A) at 900 RPM with the adaptor in the box. A 7 dB drop for 300 RPM.
- Noctua NF-A12x25: 22.6 dB(A) at 2000 RPM, 18.8 dB(A) at 1700.
- Phanteks T30: 39.7 dBA at 3000 RPM in its Advanced profile, 27.3 in Performance, and 9.8 dBA in Hybrid, which caps it at 1200 RPM.
That last one is the clearest: one fan, one spec sheet, a 30 dB spread depending only on the profile switch.
The practical conclusion is to buy fans with more airflow than you need and run them slowly, using a PWM curve or the adaptor in the box. Corsair says the same thing in its own words: PWM control lets you set speeds so fans only spin as fast as they need to, which means less noise.
Airflow or pressure
Which fan suits where depends on what it is pushing against.
Open case panels favour airflow. Noctua's NF-S12A moves 107.5 m3/h at 1.19 mmH20, which is plenty for an intake or exhaust.
Radiators and restrictive filters favour static pressure. The NF-A12x25 gives 2.34 mmH2O, the NF-A14x25 G2 2.56, and the thick Phanteks T30 7.37 mm H2O.
Fitting a low-pressure fan to a radiator is the usual mistake. It will not push enough air through the fins, so you turn it up, and then it is loud.
Mounting matters as much as the fan
Makers ship the hardware for a reason. Noctua includes anti-vibration mounts with its fans, and packs a silicone gasket with the NF-A12x25 for radiator mounting. Its NF-A14x25 G2 comes with the gasket already fitted. be quiet! supplies rubber and hard plastic mountings with the Silent Wings 4, though not with the cheaper Pure Wings 3.
Phanteks explains the design side: it keeps a 0.5 mm clearance between blade tip and frame to cut turbulence. Noctua quotes the same 0.5 mm figure for the NF-A12x25.
Bearings and how long they last
The published lifespans separate the price tiers more clearly than the noise figures do.
- be quiet! Silent Wings 4: fluid dynamic bearing, 300,000 hours.
- Noctua: SSO2 bearing, MTTF over 150,000 hours, six year warranty.
- Phanteks T30: VAPO bearing, 150,000 hours, six year warranty.
- be quiet! Pure Wings 3: rifle bearing, 80,000 hours.
Mistakes buyers make
Comparing figures at different RPM. A 13.6 at 1100 rpm and a 22.6 at 2000 are not comparable.
Expecting the number on a radiator. Every published figure is free air.
Buying pressure fans for open panels, or airflow fans for radiators. Check mm H2O against CFM.
Ignoring the adaptor in the box. Noctua's costs nothing and drops the NF-S12A by 7 dB.
Assuming Sone means decibels. ARCTIC publishes 0.3 Sone and no dB figure, so it cannot be compared with the rest.
How we chose
We read each maker's own product page, infosheet or spec sheet. We recorded every noise figure in the maker's own words, together with the RPM it belongs to and any second figure for a lower speed or profile. We compared size, speed, airflow, static pressure, bearing type, included accessories and warranty, and recorded prices only where the maker publishes one in dollars.
We did not measure anything ourselves. We ranked on published figures read together with their RPM, so a low figure at a low speed is not treated as a win over a slightly higher figure at much higher airflow. Most makers in this category sell through retailers and publish no price, which we say plainly on each pick. Fractal Design's current fan publishes 31.9 dBA and was left out, and we could not reach EKWB or NZXT.
New to the units? Read dBA explained. Wondering why two brands' figures do not line up? See why you cannot compare dB ratings across brands.
