X-bit labs

Roundup: 11 Fans for Two Super-Coolers and One System Case (page 17)

Category: Coolers

by Sergey Lepilov

[ 04/07/2008 | 07:35 PM ]

Acoustic Measurements

The next diagram demonstrates the noise level of each fan measured according to our traditional method described in the previous articles. The subjectively comfortable noise level was considered 34.5dBA and is marked with a dotted line in the diagram. The ambient noise of an open testbed without any fans on the CPU cooler was detected at 32.5dBA. The acceptable measuring error was set at ±0.2dBA.

First let’s take a look at the results obtained at a 3cm distance, when the noise meter receiver was placed right next to the fan rotor:

Now the diagram with the results obtained at a 1m distance from the open testbed:

I believe some of you will be interested in comparing this diagram with the diagram above that ranks the fans according to their official acoustic characteristics. There are a few differences but they are not crucial. Here I would like to add that all the fans up to SilverStone FM122 at ~1440RPM can be considered subjectively comfortable (or a little over), while starting with Scythe Slip Stream at ~1650RPM the airflow pushed through the heatsink plate array or through the case grids generates the noise that can hardly be considered comfortable to put up with.

When two identical fans are installed onto Scythe Infinity cooler, the noise increases by 0.2~0.7dBA depending on the type of fan and on its rotation speed. We decided not to provide a diagram here, because the fans are ranked in exactly the same order.