Noctua NF-S12B redux-700, Ultra Quiet Silent Fan, 3-Pin, 700 RPM

Have been looking for silent fans for my computer, as I am trying to make it as silent as possible. Originally had EK Vardar fans, but they were not silent, especially when at low rpm (PWM whine).These fans are not pwm (nice) and can be run at full speed while remaining almost silent. If I have no music or games making noise I can just barely make out the gentile whir of the 4 fans in my case. Now, the loudest thing in my computer is my water pump set on a very low speed.Overall I highly recommend these fans for case airflow.NOTE: I am not using the vibration damping corner pads (im cheap), and while I don't doubt that they could make improvements in some cases, in my case they are not needed as these fans are so well balanced and spin so slow they do not vibrate much at all.

First, this fan is placed on top of a class-A solid state stereo amplifier (Adcom GFA-5500) to exhaust waste heat from the chassis. Even without a Noctua ULN adapter (just a well-made inline resistor), it is nearly silent from 8 feet away. And I mean SILENT. As in no background noise, middle of the night, and I can hear my own heartbeat....and it's almost silent. With a ULN adapter, it is silent...as in 100% not audible, from 8 feet away at my listening position. In fact, with the ULN it's inaudible from 3 feet.However, and this is purely my mess-up, the fan does not function well in high-pressure (high flow impedance) scenarios. And, the coarsely perforated top grate of my amplifier is unfortunately much more like a restrictive CPU radiator than an open case. So, flow out of the top of the fan is vastly reduced when placed directly on top of the amp's top cover. Now, the fan remains silent (many do not), but the airflow is so low as to not be useful for my purposes. However, I love it so much I'm going to keep it for future use as a case fan.I would have been better off purchasing the Noctua NF-P12 redux-900 (also available here on Amazon), as that fan is designed for high pressure applications like restrictive fan grilles or radiators. However, the failure to do proper research is mine and mine alone. I have actually ordered a Noctua NF-A12x25 ULN (their newest and best fan design) from Amazon as a bit of an over-spend...but I wanted to be sure that the fan would operate as efficiently as possible with some resistance. The NF-A12x25 ULN is designed to function in the sweet spot of airflow/flow resistance that includes all common water and air cooled CPU radiators, as well as case fan use.Being a long time Noctua user I can attest to the fact that they STAY quiet for many years of continuous use (even with dust accumulation on the blades). Their stated bearing life of 150,000 hours is likely conservative. Their 6-year warranty speaks volumes.

I tried NF-A12 which runs at 1200 rpm before.This runs at 700 rpm and is noticeably quieter.Also note that sometimes you need to repin them for them to work which is a very easy task to do.

Tempted to dock a star because it's so quiet I can't tell if my computer is turning on or not. Really great fans.