NoctuaNF-A4x20 5V PWM, Premium Quiet Fan, 4-Pin, 5V Version (40x20mm, Brown)

I order two silent fans and replace a very loud original fans for network switch. Amazing performance no sound at all.

This items working perfectly more than original FANs which coming on QNAP 10g managed switch. Very quiet and cooling the switch. Highly Recommended for others

Bought this to replace my noisy 3D printer hotend fan. It is quiet now.

----- 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 VASIC Frequency: 475 MhzFan RPM Setting (Manual): 75%Caizhu Fan: 6,896 RPMBitaxe Power: 12.0 WattsASIC Temp: 47°CExpected Gh/s: 606Run Time: 15.043 hoursAverage Shares p/Hour: 378.052 (Total Shares this Session: 5,687)Shares p/Rejected: 145.821Average Rejected p/Hour: 2.593 (Total Rejected this Session: 39)Gh/s Ranges: 473-810Efficiency Ranges: 17-21 J/ThBest Difficulty (this session): 4.6MNoctua Fan: 5,538 RPMBitaxe Power: 11.6 WattsASIC Temp: 46°CExpected Gh/s: 606Run Time: 15.211 hoursAverage Shares p/Hour: 380.436 (Total Shares this Session: 5,787)Shares p/Rejected: 170.206Average Rejected p/Hour: 2.235 (Total Rejected this Session: 34)Gh/s Ranges: 442-802Efficiency Ranges: 17-21 J/ThBest Difficulty (this session): 4.01MNow, 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).

Used for a BitAxe - much quieter and better at cooling than the fan that came with it.

Habe diesen Lüfter für meinen 24/7 laufenden HomeAssistant-PC bestellt.Ich habe hierfür ein Mini-ITX Case, das Platz für ein kleines, internes Netzteil bietet - da ich dieses jedoch nicht nutze, hatte ich ein 4cm hohes "Loch" im Gehäuse. In diesen Ausschnitt habe ich den Lüfter mit einer 3D-gedruckten Halterung eingesetzt.Der kleine Lüfter ist tatsächlich, wie von Noctua gewohnt, sehr leise, fördert trotz der kleinen Größe jedoch auch noch genug Luft.Ich bin zufrieden und würde den Lüfter jederzeit wieder kaufen!

You can tell it's a premium product based on the sheer number of adaptors in the box. Its packaged like something from Apple.I had to touch it to check it was moving it is so quiet. The photo shows it zip-tied to my 10G network card whose max temp it's dropped by 20c

Always high quality fans from Noctua.