Fan Speed, Noise, And Value
Fan speed is the biggest factor in both noise levels and airflow, two things that manufacturers must carefully consider before launching any new cooling product. One might thus expect the noisiest cooler to be the most powerful, although sink design is often more important.
Thermalright’s moderate cooling performance is achieved with a surprisingly low-speed fan, while Thermaltake’s Frio spins over twice as fast at maximum speed. Potentiometers on the Frio’s fans allow these to be slowed, but it would have been impossible test the infinite number of available settings.
Running at slightly less than its rated speed, our Thermalright MUX-120 sample also produced slightly less noise than its rated maximum. Scythe’s second-place quietness is impressive in light of its second-place cooling performance.
The easiest way to figure out which cooler provides the best cooling-to-noise ratio is to convert each observation to a percentage, relative to other coolers in the test. We divided the average temperature produced by all coolers by the actual temperature produced by each cooler to create a temperature-percent scale. A separate noise-percent scale divides each cooler’s SPL by the average noise of all coolers. Dividing each cooler’s temperature ranking by its noise ranking allows a number to be assigned to its acoustic efficiency, aka "cooling-to-noise ratio.”
Thermalright’s supremely quiet fan and mid-pack cooling performance team up to give the MUX-120 a first place cooling-to-noise finish. Scythe’s mid-speed fan and huge sink allow its Mugen-2 Rev. B to retain second place.
Applying the same calculation method used above to temperature and price allows value to be assessed numerically.
The above chart comes with a big caveat: while Cooler Master’s Hyper 212 Plus provided enough cooling for our 4 GHz CPU, the Freezer 7 Pro Rev.2 did not. Thus, while Cooler Master’s low $30 price makes it a great deal for ambitious overclockers, the Freezer 7 Pro Rev.2 is better suited for less enthusiastic tweakers.