Cooling Efficiency Tests
Dependence of Cooler Efficiency on Fans Number and Rotation Speed
In this test session the maximum frequency of the Intel processor was limited by the performance of the Alpenföhn Nordwand cooler with one standard fan at 600 RPM. It was 3885 MHz at a voltage of 1.325 V. I also tested the cooler with two Thermalright TR-FDB fans. The fan speed was adjusted with a step of 200 RPM (±20 RPM). The side panel of the system case was open during the tests. Here are the results:
It is easy to note that the efficiency of the Alpenföhn Nordwand depends heavily on the speed and number of its fans. The CPU temperature changes by 15°C when the default fan’s speed is increased from the minimum 670 RPM to 1220 RPM. Accelerating the fan above 1400-1500 RPM is not rewarding because the fan becomes loud while the temperature does not lower much.
Besides, my supposition that the default fan of the Alpenföhn Nordwand had a low static pressure seems to be true. At the same speeds a single Thermalright TR-DBH fan ensures more effective cooling of the heatsink plates and, consequently, a lower temperature of the CPU. Adding a second Thermalright fan to exhaust the air out of the heatsink helps reduce the peak CPU temperature by 11°C at a nearly-silent 600 RPM, by 4°C at 1000 RPM and by 2°C at maximum speed.