Acoustic Performance

First of all, let’s see what noise Zalman CNPS10X Extreme generates in the entire supported speed range of its default fan (power consumption data are a nice bonus here):

If the fan rotation speed doesn’t exceed 1070 RPM, the Zalman CNPS10X Extreme cooler can be considered quiet. And at about 1300-1350 RPM it can be called subjectively tolerable. Unfortunately, you can heat slight rustle of the dual ball bearing at low fan rotation speed. In fact, it is similar to the rustling sound from Scythe Minebea Silent IC bearing. I would like to add that the fan startup voltage is 6.3 V and in terms of power consumption, it is hardly an energy-efficient model. We detected no tinkling of the heatsink plates or plastic parts within the entire fan rotation speed range. It is really hard to find any problem here, because the quality of Zalman CNPS10X Extreme assembly is truly high.

Now let’s compare the acoustic performance of all tested coolers in the same fan rotation speed modes as we took for the cooling efficiency tests. The fans were installed exactly the same way as shown on the photo above. They were working for air intake-exhaust on both sides of ThermoLab BARAM heatsink. As for Thermalright IFX-14, one fan was installed on the inner side of the first heatsink array along the direction of the airflow, and another one – on the outer side of the second heatsink array (using rubber bands). Let’s take a look at the comparative diagram now:

The results of our noise measurements performed outside the system case confirmed one very interesting supposition: the shape of the cooler heatsink does in fact affect the level of noise. For example, let’s take the results of Zalman CNPS10X Extreme and ThermoLab BARAM coolers tested with the same fan at 1110 RPM: the noise level of the Zalman solution is lower in this case. At maximum rotation speed of the Noiseblocker fan the situation repeats. Moreover, when we installed two fans onto BARAM cooler, its fan starts jingling at any speed. And while this sound is barely noticeable at the lowest fan speed, then at maximum 1760 RPM it becomes pretty annoying, I have to say. At the same time, the use of two fans on Thermalright IFX-14 causes no jingling of any kind. As for the results of Zalman CNPS10X Extreme with a default fan versus an alternative Noiseblocker fan, the cooler works at even higher rotation speed with the latter, which is, in fact, quite expected.