Review on Noctua NF A4X20 FLX Premium 40X20Mm by Gregory Shin

Although they are quite expensive for their category and size class, I think they are worth it. I've heard a lot of good things about this brand and I had to replace the two 40mm fans in the Icydock 2.5" 6-sat hot-swap hard drive bay. The fans I replaced were just ordinary crappy low density polyethylene fans that had failed bearings and just generally crappy construction. As an experienced engineer who works at a high level in both several technical fields and information technology, I will say that these are probably the highest quality consumer goods. Great fans I've seen. The build quality and material quality are excellent and a lot of effort has gone into the product design and construction. I personally don't care how something looks as long as it serves its purpose and has a very long maintenance cycle. I would like to order certain Noctuas without anything superfluous. I would never use anything other than the fan itself and possibly the rubber mounts that come with it. I will always use 3-4 pin connections if available with DC or PWM speed control. The speed adapters are probably just resistors in series to limit the current going to the fan, which is wrong practice but I think it works if you only connect to a DC power source. The components in my shipment went to the parts store for some project or something in the future, if ever. I had to cut, solder and crimp both harnesses as my application requires very short lengths (less than 1 inch each) and has very little space. Once installed I am very happy with the noise level, static pressure and apparent flow, especially for a 40x20 fan. I am using a solid state controlled constant current driver with speed feedback for each fan. The drives they cool are extremely important; They're hosting a six-drive RAID array with all my critical data, so it's imperative that the drives stay cool and the fans are quiet and reliable. Simply put, fans are absolutely expensive, but they deliver on their promises exceptionally well. I will be considering this brand for all my future consumer fan purchases (I currently use high static pressure Corsair fans).