This thing is monstorously huge, and PC Perspective takes this bad boy for a spin. The XP-120 heatsink uses five copper heat pipes to transport heat from the heatsink base up to the large surface area provided by the copper fins. A heat pipe is a highly efficient conductor of heat. A properly constructed heat pipe has a very low thermal resistance, which is roughly independent of its length (unlike ordinary metal rods whose thermal resistance increases with length). Heat pipes are commonly used to transport heat from one location to another. Having a 120mm fan cooling your Athlon 64/FX or Socket 478 Pentium 4 should give you some nice temps without having to go to watercooling. It may also make some people pass out at the sight of the thing. Anyway, here's the review.