Test Setup

My standard fan-testing methodology involves a decoupling of external variables from the fan itself. As such, I do not test fans by measuring the CPU temperature as cooled by a heatsink with the fan on it, for example. A fan's only purpose is to blow air through and counter airflow restriction, so for the category of watercooling here, I pick a single 120 mm radiator with an average airflow restriction of all other radiators at the time of testing, which had me settle on the Swiftech MCR120QP. Note then that I am using the radiator to test for a single point of airflow restriction at each fan speed so. While it is not mapping out the entire P-Q chart of the fan, which takes very expensive equipment to do accurately, it is also more reliable. I used to measure linear airflow in FPM (feet per minute) and continue to do so on my own website, but thanks to an offer from Corsair, I decided to adopt a new setup for TechPowerUp that will also help with a start from scratch for a new database of results.


Corsair had contacted me several press outlets earlier this year with a no-strings-attached offer of a mini wind tunnel to aid in better testing fans. Pictured above, it consists of a 1 m tall cylinder made out of acrylic (6" OD, 5.75" ID) with two flow straighteners inside out of a metal wire screen placed 50 mm and 100 mm from the exhaust, and inlet/exit holes of the surface area, which in turn is the surface area of the airflow field exiting the tunnel. On the entry side are threaded holes for 120 mm fans, with an adapter plate for 140 mm fans provided as well. In hindsight, their offer makes a lot of sense given they have released three new fan series since this came in, and understandably, they want their products to be tested as well as possible.


To quantify airflow, I had the fan of choice, the Darkside Gentle Typhoon 1450 RPM in this case, screwed into the radiator, which in turn was secured in place via another set of short screws through the adapter plates as seen above. A calibrated Omega HHF-308 Thermo-anemometer was used on the exit side, held in place by a hook and loop fastener, to measure linear airflow which multiplied by the surface area of the exit circle provides the volumetric flow rate.

The fan under review was then controlled by an Aqua Computer Aquaero 6 XT in volume-control mode, and the RPM response was recorded as a function of applied voltage. The anemometer measured the airflow through the radiator for an average of 15 minutes per RPM value, and fan noise was measured separately in an anechoic chamber of 5′ x 8′ in size with ambient noise at ~19 dBA over a sound probe held 6" away to measure the sound volume in dBA. This then generated RPM, airflow, and noise measurements.