Which 200mm fan is the quietest?
Inside Noctua, the NF-A20 PWM and FLX tie at 18.1 dB(A) for 800 RPM. Inside Thermaltake, the CT200 leads at 27.2 dB-A.
| Fan | Figure | Speed it belongs to |
|---|
| Noctua NF-A20 PWM | 18.1 dB(A) / 10.7 dB(A) | 800 RPM / 550 RPM on the adaptor |
| Noctua NF-A20 FLX | 18.1 dB(A) / 10.7 dB(A) | 800 RPM / 550 RPM on the adaptor |
| Thermaltake CT200 | 27.2 dB-A | Not stated, PWM range 500 to 900 RPM |
| Thermaltake Pure 20 | 28.2 dBA | Fixed 800 RPM |
A 9.1 dB gap between Noctua's 18.1 and Thermaltake's 27.2 looks decisive. It proves nothing until either maker says how it measured.
Brands are compared only with themselves
Sound fades as a meter moves away from the source. A reading taken at one meter and one taken at ten centimeters can differ by many decibels for the same fan, and none of the 200mm makers whose pages we checked gives a microphone distance or a test standard, so a Noctua dB(A) and a Thermaltake dB-A may not describe the same measurement at all. Our decibel rating comparison explainer covers why that one missing line breaks a cross-brand ranking.
Speed is the second gap. Noctua ties each figure to an RPM, and the Pure 20 names its single speed, but the CT200 and Cooler Master's SickleFlow 200 ARGB print one number beside a range without naming the point in it.
The NF-A20 drops 7.4 dB on its adaptor
With the Low-Noise Adaptor in line, the NF-A20 falls from 18.1 dB(A) at 800 RPM to 10.7 dB(A) at 550.
That quiet costs air. At 800 RPM the fan moves 146.9 m3/h against 1.08 mmH2O; at 550 it moves 100.8 m3/h against 0.51 mmH2O. Pressure roughly halves, a real loss behind a dense dust filter or a mesh front.
Every 10 dB reads to the ear as about half as loud, so 7.4 dB is a big step for one fan. Our decibel chart puts single-digit and teen figures beside everyday sounds.
The PWM model can reach both speeds without the adaptor. A motherboard fan curve lets it idle low and climb under load.
A 4-pin motherboard header calls for the NF-A20 PWM. A 3-pin header or a fan controller suits the FLX. Noctua's sheets give the pair the same noise, airflow and pressure, and both measure 200 x 200 x 30 mm, run on an SSO2 bearing and draw 0.96 W at 12 V.
The FLX sheet says it "provides 800/550rpm speed settings via the supplied Low-Noise Adaptor", which suits a builder who wants a fixed speed and no software.
Two other NF-A20 versions are not picks. The chromax.black.swap edition of the PWM model had a product page that would not load for us on November 7, 2026, so no figure is quoted for it. The NF-A20 5V PWM is not a PC part at all: Noctua says it "will be damaged when used with typical 12V power sources such as PC motherboard fan headers."
Every other Noctua size is on our Noctua fan decibels page, with each model's sheet figures.
Thermaltake's CT200 sits 1 dB under the Pure 20
Thermaltake's pages give the CT200 27.2 dB-A and the Pure 20 28.2 dBA, with the CT200 moving 2 CFM more.
The hardware differs more than the noise does. The CT200 is a PWM fan running from 500 to 900 RPM on a hydraulic bearing rated for 40,000 hours, at $19.99. The Pure 20 is a fixed 800 RPM, 3-pin fan on a sleeve bearing rated for 30,000 hours, at $13.99. Only the Pure 20's figure is tied to a speed, because the CT200's single number covers its whole range. The lit CT200 ARGB Sync repeats the 27.2 dB-A row at $24.99.
The page gives 15.7 dBA beside a speed of 0 to 800 RPM, for a 200 x 200 x 25 mm fan that moves 102.8 CFM.
At 25 mm it is the thinnest 200mm fan here, 5 mm slimmer than the NF-A20 or either Thermaltake. It runs on a sleeve bearing with an MTTF over 160,000 hours, puts its ARGB lighting on a separate 3-pin connector and carries a three year warranty.
Two things kept it out of the picks: the figure names no speed, and on November 7 the only new Amazon listing we found came from a third-party seller marked low stock.
Will a 200mm fan fit your case?
Only if the case's holes and depth match. Noctua says 200mm spacing has "no fixed industry standard", which is why the NF-A20 carries three hole patterns.
Its sheet explains that the "154x154mm and 110x180mm spacing allow it to replace most 200mm fans", while a third pattern, 170 x 170 mm, lines up with many 230 and 250mm fans.
Depth catches people out. The NF-A20, CT200 and Pure 20 are each 30 mm deep, and Noctua warns that some other 200mm fans are only 20 mm, so a fan that thick can collide with a radiator, drive cage or front panel that a thinner one cleared. Measure before ordering.
Still choosing the case? Our quiet PC case guide lists cases that arrive with big fans fitted.
180mm fans use different holes
SilverStone's AP181 is a separate size with its own mounting, so it sits apart from the 200mm fans. It matches three speeds to three figures:
| AP181 setting | Noise | Airflow |
|---|
| 600 rpm | 15.9 dB(A) | 52.4 CFM |
| 900 rpm | 24.75 dB(A) | 78.68 CFM |
| 1200 rpm | 30 dB(A) | 100.27 CFM |
It is 32 mm thick, runs on a sleeve bearing and has a speed control cable for choosing the setting. Amazon showed it only in low stock on November 7.
Fractal Design once sold 180mm Dynamic X2 GP-18 and Prisma AL-18 fans. Those pages now redirect to a fan range listing only 120 and 140mm models.
Brands missing from this guide
Phanteks, Lian Li, NZXT and Antec are absent. We found no current 200mm fan from them carrying a figure we could confirm and buy new on Amazon.
Phanteks' PH-F200SP is still on Amazon, but phanteks.com returns "Page not found" for it, as did the Internet Archive's copies from March and October 2026. Our Amazon searches turned up no 200mm fan sold under Lian Li, NZXT or Antec.
Quiet fans in every size are collected in our PC fan guide.
How much does a quiet 200mm fan cost?
From $13.99. That is the Pure 20 on Thermaltake's US store on November 7, 2026, followed by $19.99 for the CT200 and $24.99 for the CT200 ARGB Sync.
Noctua lists no prices and sends US buyers to its Amazon store. Cooler Master and SilverStone show none on their product pages either.
