Very good quality, top processing

Small update on my part:
I currently run a Costum-water cooling with 6 fan places (2x360er radiator). On this, the NF-F12 PWM PPC 2000 are currently 6x installed.
Unusual operating in me is none yet. However, had a defective new, he had a problem with the cable. Was sent back ordered new at the same time &.

What makes the difference between PWM and the normal version? Which version should I buy?
PWM is a control technology. If one has a fan controller with 4-Pin fan connector or a corresponding mainboard, I advise always to take PWM fan.
Have in the current system, here are the PPC 2000 Try without PWM. Running the same way. But have a (big?) Disadvantage. The minimum speed of the "normal" -3Pin fan is approximately 900rpm. Furthermore are fans that are controlled by the current, less efficient, since the regulation is done with resistors, which are then very warm.
In PWM, however, we have concerns always 12V and the fan turns at very short intervals in & out (Simplified principle of PWM).

So we can come to 300rpm speeds below that which will never be possible with a 3pin fan with the NF-F12 PWM PPC 2000.
Especially for heatsink (whether radiator or CPU cooler tower does not matter) so you can hammer out a Airflow, without even realizing that the fans run. This achieves better temperatures than only with passive cooling.
So I can lay you the PWM fan to the heart.

For volume (subjective attitude!):
At approximately 0-700 revolutions they are imperceptible. My HDD's are in the revolutions loud (sorry :(). From 1000 to 1200 revolutions you realize now already that the fans move a little more.
From about 1600 and upwards, with some resistance from the case then you have small turbines. Literally. Are loud audible, but they promote so damn much air. Thus each, but really any system remains cool.

The processing is very clean and they are very sturdy. Until something breaks down, EHR breaks anything.