PWM fan or not?Over the last few years PWM or Pulse Width Modulation style control has become more and more common for fans. This type of fan is easy to recognise as they don’t use a 3-wire standard connector but a 4-wire one.
A standard DC fan with three wires is supplied with 12V and you simply reduce this to reduce its rotation speed. The PWM is quite different because you stay at 12V but a series of very rapid stop/start signals are sent to the fan via the fourth wire. The frequency of these signals regulates the fan speed, generally resulting in more precise and immediate control.
These advantages are nevertheless pretty limited in practice and PWM mainly just simplifies motherboard handling of fans – simpler integration of circuits than for standard DC regulation. As most motherboards have abandonned regulation by DC fans in favour of PWM, fan manufacturers have generally followed the market. In this report, only Noctua, NZXT and Scythe (for its Susanoo) still use a standard DC power supply.
Simple installation or not?
The coolers in this comparison are generally easy to install. You do however need a little more patience than with the entry-level models as you are systematically required to mount a support plate at the back of the motherboard, which is logical considering how heavy these beasts are.
If there isn't enough space at the back of the motherboard in your casing, you'll need to dismount it to get the cooler in there. With such a case, you sometimes have to dismount the whole system as it can be easier to mount the cooler outside the case, especially when you have to screw the cooler to the back plate as you have to do with the Scythe and be quiet! solutions.