ZEROtherm's alternative to the BTF series coolers, the CF900 couldn't look any more different. Yes, it uses the same heatpipe technology to move the heat away from the heart of the CPU, but that is where the similarities end. There is no mention of insects that it may resemble, it is a first and foremost a CPU cooler designed to do just that, keep your CPU cool.

Rather than using a square fan ZEROtherm have designed a fan that maximises the available space. This means more airflow can be provided compared a smaller fan at the same noise level. Another feature about the fan (and this is the biggest selling point) is that it is temperature controlled. I hear you say that the BTF CPU coolers are also temperature sensitive, well you are right but those coolers use PWM fans, which means the fan speed is dictated by the BIOS settings in the motherboard. If you do not feel confident in changing BIOS setting the CF900 is ideal because you to no need to change anything in the BIOS because the supplied fan is a standard 3-pin fan and not PWM.

The fan speed is controlled by a thermistor which rests in the main body of the fins. When the fins heat up the thermistor then increases the fan speed to compensate. As you can imaging when the system is first switched on the fan is extremely quiet because the heatsink is very cool. Depending on what applications are running will determine the CPU temperature and then therefore the fan speed and noise.

During our testing we were very pleased at the rate the fan speed increased and the extra cooling the increase provided. But what is important about a temperature controlled fans is that the fan speed is reduced when CPU intensive activities cease. We are happy to say that the fan did not let us down. Once the CPU temperature dropped so did the fan speed and therefore the noise.

The CF900 cooler is compatible with Intel's socket LGA775 only. It is attached to the motherboard very securely using screws. This means the motherboard will need to be removed from the system for it to be installed.