Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)

Bought an old 4 bay 1U rackmount NAS from eb** and was shocked how noisy it was. 60+db while building a raid array. So thought not happening and went looking for silent fans, found these and read the reviews and being a Scotsman I was like seriously? for a wee fan like that? and there were 3 system fans and 1 power supply fan. I was aboot greetin.Bought the 4 fans and proceeded to swap them out taking measurements along the way. After replacing the 3 system fans the noise level dropped to a low of 21db and peak of 25db system temp 1degree lower CPU temp 1 degree higher.I then swapped the power supply fan and set the system to rebuilding a raid volume, which is possibly the most intensive thing a NAS is going to do and it is quite happily purring along at a peak of 18 db with a system temp 2 degrees lower and a CPU temp 1 degree higher than factory fitted fans.I should mention that I am using the low noise adaptor cables that come supplied in the fan kit for the 3 system fans.The kit is well supplied with everything you need and gives you options aplenty for extensions and fitting methods.The quality seems to be superb and longevity is backed by their guarantee.I will be buying these fans exclusively from now on and upgrading all fans in my servers.The only nark I would have is the colour! My god it's awful lets have some bright colourful options yellow/black red/black etc, something to indicate that it's a premium high performance fan. Lookswise it definitely needs some cool.Other wise very happy if not skint wee laddie but well worth it.

I bought this as a replacement fan for my Dreamcast. It was super easy to install (with the Noctua fan kit sold separately) and runs super quiet, unlike the stock Dreamcast fan, which is a noisy little beggar. It was great value for the money and has also increased the airflow through my Dreamcast.

I bought a few of these to cool my TP-Link SX3016F switches as the built in units were noisy as heck.Now before anyone says it, yes these move less air-flow so I was initially hesitant to complete the switch but my ears have thanked me and after running a temperature probe inside the units there has been no actual increase in operating temperature.As most are probably aware with Noctua it is definitely function over form however for the purpose of these units that is absolutely fine and Noctua once again have not disappointed me

The Noctua NF-A4x10 FLX is nothing short of a fanatical fan's dream come true. This little marvel has left me awestruck, and it absolutely deserves a solid 5-star rating. Let me break down why this fan has me singing its praises, and don't even get me started on the vast array of included accessories.Silent Powerhouse (5/5): First things first, the noise level - or should I say, the lack thereof. This fan is so quiet; it's like a whisper in a library. You can barely tell it's running, even at full tilt. It's a game-changer for anyone who values a peaceful computing environment.Impressive Cooling (5/5): Despite its tranquil operation, this fan knows how to keep things cool. It might be small, but it packs a punch when it comes to airflow. Whether you're cooling your CPU or improving case ventilation, it gets the job done efficiently.Flexible Speed Control (5/5): The FLX in its name stands for "flexible," and it lives up to the title. With the included Low-Noise Adapters and Ultra-Low-Noise Adapters, you can fine-tune the fan's speed and noise levels to your exact liking. It's all about customising your cooling experience.Noctua Quality (5/5): When you invest in a Noctua product, you're investing in quality. This fan is no exception. The build quality is top-notch, and it comes with a 6-year warranty, which speaks volumes about the manufacturer's confidence in their product.Easy Installation (5/5): Installing this fan is a breeze. Noctua includes all the necessary mounting hardware and even provides clear, concise instructions. Even if you're not a tech wizard, you'll have no trouble getting this fan up and running.Now, let's talk about the incredible array of included accessories. Noctua doesn't just give you a fan; they provide a complete package. You'll find a variety of adapters, extensions, and even a low-noise adapter, allowing you to tailor your setup precisely to your needs. It's like a treasure trove of options for achieving the perfect cooling solution.I must add that I used this fan to replace the noisy Hikvision NVR standard fan. The difference was night and day. No more intrusive fan noise disrupting my work or leisure. In a nutshell, the Noctua NF-A4x10 FLX is a silent powerhouse that's perfect for anyone who demands both performance and tranquillity from their cooling solutions. Its ability to keep things cool without uttering a peep is nothing short of remarkable. Whether you're building a new PC or looking to upgrade your existing system, this fan is a game-changer. I couldn't be happier with my purchase, and I highly recommend it to fellow PC enthusiasts. It's a 5-star gem! ⭐⭐⭐⭐⭐

Great, quality quiet fan.It's very quiet and give great cooling.

Grabbed myself a few of these for some 10Gbe NICs and a HBA. Absolutely silent but move enough air to pull a ~90c ethernet NIC that was thermal throttling and shutting down the port, to a much more sensible 55c that can saturate the 10Gbe link endlessly.My only gripe here is the price for what you get, and hence why I've dropped a star. They're not priced all that much cheaper than the full size 120mm fans. But, Noctua is Noctua, and you know what you're in for when you're buying their products (supreme longevity and silent operation). I know I'll be back for more the next time I need a silent fan.They do include some pretty cool cable connector types in the box though! They know many users will be snipping off the included connector and soldering these directly to PCBs or tapping off of non-PC standard headers. So bonus points for this thought process.