In this review Frostytech is testing out Xigmatek's new HDT-S983 heatsink, an innovative thermal solution that employs sculpted & textured aluminum fins, and large copper heatpipes that make direct contact with the CPU.
If you take the Xigmatek HDT-S983 and look at the bottom you'll see an aluminum base with three 8.5mm wide grooves cut deeply into it. Set snugly within each groove is an 8mm diameter copper heat pipe, which has been flattened so everything is flush. Instead of using a bulky copper plate, Xigmatek use the superior heat conducting capabilities of heat pipes to conduct heat away from the core of an AMD or Intel processor. The to three 8mm diameter copper heatpipes transfer that heat rapidly to a large array of sculpted and textured thin aluminum fins above.
FULL STORY @ FROSTYTECH (http://www.frostytech.com/articleview.cfm?articleID=2219)