









🛠️ Silent strength in a compact package — cool smarter, not louder!
The Noctua NF-A4x20 5V PWM is a premium, ultra-quiet 40x40x20 mm cooling fan designed for 5V applications with PWM speed control. Delivering up to 5000 RPM at a whisper-quiet 14.9 dB(A), it features advanced aerodynamic design and acoustic optimization for superior cooling performance. Ideal for compact devices like NVIDIA Jetson Nano, network equipment, and 1U servers, it boasts a robust >150,000 hour lifespan and comes with a comprehensive mounting kit for easy, vibration-free installation.












| ASIN | B071FNHVXN |
| Best Sellers Rank | #113 in Computer Case Fans |
| Brand Name | Noctua |
| Compatible Devices | Desktop |
| Cooling Method | Air |
| Customer Reviews | 4.7 out of 5 stars 3,666 Reviews |
| Global Trade Identification Number | 09010018100136 |
| Item Dimensions L x W x H | 1.57"L x 0.79"W x 1.57"H |
| Item Height | 4 centimeters |
| Item Weight | 84 Grams |
| Manufacturer | Noctua |
| Material Type | Fibre-glass reinforced PBT |
| Maximum Rotational Speed | 5000 RPM |
| Noise Level | 14.9 Decibels |
| Power Connector Type | 4-Pin |
| Unit Count | 1.0 Count |
| Voltage | 5 Volts |
| Warranty Description | 6 year manufacturer’s warranty |
B**.
Best fans money can buy
The best fans that you can buy for your application. Very durable and well built The included hardware is top notch and the splitter is such a welcome addition to have. I have three of these all cooling my BitAxe miners and they are very efficient and quiet, even when running at higher rpm's. Expect Noctua fans to last longer than your electronic device. Just clean then every so often of dust that can accumulate on the fans and you can expect them to have a very long lifespan.
G**R
UPDATE: Super quiet fan, [give it a shot!]
----- Start of Update 12OCT24 ----- The Noctua Fan had previously received many high regards, so I decided to run it longer term and compare it with the orginal Caizhu Fan on the Bitaxe 401 Supra. One can fully customize the settings to run at varying input voltages and pair them up with varying frequencies. I just "picked on" one setting and ran the Bitaxe with the original fan (Caizhu), then the Noctua, as follows: ASIC Voltage Requested: 1.166 V ASIC Frequency: 475 Mhz Fan RPM Setting (Manual): 75% Caizhu Fan: 6,896 RPM Bitaxe Power: 12.0 Watts ASIC Temp: 47°C Expected Gh/s: 606 Run Time: 15.043 hours Average Shares p/Hour: 378.052 (Total Shares this Session: 5,687) Shares p/Rejected: 145.821 Average Rejected p/Hour: 2.593 (Total Rejected this Session: 39) Gh/s Ranges: 473-810 Efficiency Ranges: 17-21 J/Th Best Difficulty (this session): 4.6M Noctua Fan: 5,538 RPM Bitaxe Power: 11.6 Watts ASIC Temp: 46°C Expected Gh/s: 606 Run Time: 15.211 hours Average Shares p/Hour: 380.436 (Total Shares this Session: 5,787) Shares p/Rejected: 170.206 Average Rejected p/Hour: 2.235 (Total Rejected this Session: 34) Gh/s Ranges: 442-802 Efficiency Ranges: 17-21 J/Th Best Difficulty (this session): 4.01M Now, other settings can render different results, but I will just say the obvious, the Noctua doesn't need to spin faster to move more air, it's designed that way, it's why it's good (and I was too quick to judge). It allowed the Bitaxe to consume a bit less power, run 1°C cooler and was also a bit more efficient in the long run. After giving it a fair shake over the last week, I prefer the Noctua over the Caizhu and I know someone else in the house that REALLY appreciates how quiet it runs. I would purchase a Noctua fan for any future Bitaxes that I acquire. Rating increased from 4 to 5 Stars. ----- End of Update 12OCT24 ----- The NF-A4x20 5V PWM came in a fancy package, with wiring adapters and mounting hardware. I just needed the fan. This fan is the fastest of the Noctua fans, rated at 5,000 RPM +/- 10%, which mine ran at just over 5,400 RPM when I installed it on the Bitaxe 401 Supra. I was disappointed to find that at MAX RPM (5,400), it did not move more air than the stock CAIZHU-FAN (I ran it at 6,750 RPM, or 88% fan speed on the Bitaxe). Even at the MAX speed of 5,400 RPM, the Noctua allowed my Bitaxe to run 6°C hotter than with the CAIZHU-FAN at 6,750 RPM (88% of MAX speed). Furthermore, this Noctua fan causes my Bitaxe to consume 16.2 Watts, versus 15.2 Watts with the stock fan. So, in short, it moves less air and consumes more power :^| On the other hand, the Noctua runs extremely quiet, as advertised "14.9 dB(A)", while the CAIZHU-FAN runs a bit noisy, especially when passing 5,000 RPM. It's up to you. Do you want to run your Bitaxe hotter by 6°C and consume an extra Watt of Power, but it's much quieter? Do you want the sound of the fan in the background, evidence of work in progress, but the Bitaxe runs better? If Noctua would make a 40x40x20 5V PWM fan that was rated at 8,000 RPM, I would love to compare that in operation to the stock CAIZHU-FAN on my Bitaxe 401 Supra. If it cools more, I would be a fan of the Noctua (pun exquisitely intended).
V**C
You can't go wrong with Noctua
I mean, Its a noctua fan. What more do I have to say? It is exceptionally quiet. Pushes a nice amount of airflow for its size.
M**N
Excellent, virtually silent fan from Noctua for Jetson Nano
Unless I'm running something intense, the PWM fan is usually off. Then when the Jetson Nano gets warm the fan turns on just enough to cool it. I never notice this fan - I have to look at the blades to see if it's spinning because it's so quiet. The default fan I replaced came with a third party acrylic Jetson Nano case, it was not PWM, always running full speed and a noisy little fan at that. I've seen other comments on the default fan saying it's not very loud. I suspect the low quality, default case fan varies in noise from unit to unit. If you want quiet - Get the Noctua PWM! I got the thick one, so I had to find some longer screws. I should have gotten the thin one which I expect would work fine and use the existing HW. At any rate, if quiet and sanity are worth a couple coffees to you, get the Noctua PWM fan, such an improvement over the default fan that came with the third party Jetson Nano case.
J**K
Awesome little fan for Raspberry Pi
Looked up the wiring diagram on Noctua to make sure I had it right, looked up an easy little PWM can script, and fired right up. Only had to plug it into 5V, Ground, and the PWM pin set in the script. Works awesome, and it's the same price as the non-PWM fan. It's almost silent if you're right by it. If your more than a few feet away you won't hear it on high. What's not to love?
D**R
Noctua NF-A4x20 5V PWM, Premium Quiet Fan, 4-Pin, 5V Version (40x20mm, Brown)
Very nice High quality replacement fan. I used it to replace a Dyeing OEM fan on a Fan kit for a USB Miner. See: https://www.amazon.com/dp/B0BKRD5BM3?psc=1&ref=ppx_yo2ov_dt_b_product_details Takes a bit of basic skills to swap out. Snipping wires on the Original Fan USB A cable, and then connecting it to this fan using supplied connectors or soldering then Shrink tubing / insulation. If your skilled and picky use soldier to connect then insulate individual wires. Works well, more blades than the Original fan, super quiet as a new item. Time will tell.
P**N
Nice little fan
This is a very good fan that fitted well on my Nvidia Jetson Nano. It has a very low noise when it is running at full speed. I did some experiments by running various loads on the CPU to see how it behaves and it worked really well to keep the CPU temperature at the set value. It has a very pleasing color combination for the fan and the outer cover. The package comes with attachments (cables) and screws. The only problem I had fixing it on the heatsink was that the screws were slightly bigger than the heat sink, but I just swapped it with another set of small screws that fit well.
L**O
Great little fan
Got this to replace the stock fan on a bitaxe, works good and is silent. Would buy again.
Trustpilot
2 months ago
2 weeks ago