120mm, 240mm etc—
These are categorized by how large their radiators are. The smallest use a radiator that’s the size of a single 120mm case fan—it’s these that don’t have the cooling power for Threadripper and Socket 2066/2011 processors. Then there are double-length 240mm radiators, and even larger 280mm radiators that use 140mm fans. The bigger the cooler, the greater the cooling ability, and the slower the fans spin to keep things quiet.
Thermal Design Power (TDP) is the maximum heat generated by a chip. It’s good for telling how powerful a cooler you’ll need.
We’ve measured the noise created by each of these coolers, measured in decibels (dB). This is a logarithmic unit, so if something is 10dB louder it’s actually 10 times as loud. Therefore just a couple of dB difference in our coolers is significant. Ambient noise in our test labs was 30dB, and noise levels were measured 30cm from the cooler.