X-bit Labs has published a roundup of 11 fans from Cooler Master, GlacialTech, Noctua, Scythe, Silverstone and Zalman.
They differ not only by their dimensions and rotation speed. Although these are very important characteristics, they are still only the top of the iceberg. If you dig a little bit deeper, you will also find out that the fan differ by a number of other characteristics such as number and shape of the fan blades, type of bearings and their MTBF, noise level and airflow, static pressure and power consumption, and a few others.
Overclocking fans favor mostly 120x120x25mm fans as these are the most widely spread fans in contemporary CPU coolers as well as power supply units, which is also pretty important. That is why we put together a test session involving almost a dozen fans from six well-known manufacturers.