Like heat pipes, vapor chamber thermal conductivity increases with length. This means that a vapor chamber the same size as the heat source will offer little advantage over a solid piece of copper. A good rule of thumb says that the area of the vapor chamber should be equal to or greater than 10X the area of the heat source. In situations where the thermal budget is large or when a lot of airflow drives a small fin stack this may not be an issue. However, it’s often the case that the base of the sink needs to be considerably larger than the heat source.
Vapor Chambers are designed for vastly improved thermal performance over traditional solid metal heat spreaders found in traditional CPU coolers. This is accomplished while achieving a reduced weight and height. Vapor Chamber technology enables higher CPUs with a higher TDP (or overclocked state) to be efficiently and effectively cooled to safe operating temperatures, extending component and product life.