Originally Posted by xartemporas
I have read some reviews, it seems to have better performance and generally have slim design, works with less rpm but it doesn't have pwm(what exactly is this?).
I Can find it in almost the same price with 212 evo.
Choice is really yours to make- size, style, and installation will be similar to the 212. If you like the reviews on them and the 212 isn't available then give it a try... it's not a big difference in cost...
PWM (pulse width modulation) is a type of control for the fan and is the preferred method to control the speed of a CPU fan as it allows the motherboard to control fan rpm based on CPU temp, etc. Standard fans have an RPM sensor and can vary in speed but not automatically
How to tell them apart:
PWM fans have 4 wires vs 3 wires for a regular fan. PWM fans also cost more. PWM is the better choice if you are comparing 2 coolers at a similar price (i.e. buy the model with the PWM fan)