Elite Bastards posted Gelid Solutions Silent 12 TC and PWM cooling fan review
A quote from the article:
>> Gelid Solutions Silent 12 TC and PWM cooling fan review
The basic bundle for the Silent 12 PWM is the same as the TC unit, including that sticker and rubber grommets for installation. However, as the name suggests this particular unit alters its fan rotation speed based around the PWM (pulse-width modulation) data provided by the system, so that it can regulate itself against CPU temperature. This does however require a four-pin fan header on the motherboard rather than the usual three-pin connector, so make sure your motherboard has sufficient four-pin headers free for installation.
>> Gelid Solutions Silent 12 TC and PWM cooling fan review