Innovative Technique 1:
First off is Xigmatek's "Heat-pipe Direct Touch"; essentially just placing the heatpipes at the bottom of the heatsink so they directly contact with the top of the processor. This arrangement minimizes thermal resistance as heat energy is conducted directly to the heatpipes, instead of through a base plate, solder joints, then to the heatpipes as in a traditional cooler. The heatpipes, which are a larger diameter than the standard 6mm variety, thread up through the many aluminum cooling fins where heat is dissipated into the surrounding air mass.

Innovative Technique 2:
Most heatsinks have flat metal fins, sometimes with little bumps or ridges to stiffen them. Xigmatek have built the HDT-S983 heatsink with widely spaced aluminum fins, that curve down in the center. This helps lower velocity air pass through the heatsink with less resistance, while funneling air towards the regions of the aluminum fins adjacent to the 8mm dia. heatpipes. Small dimples in the fins create extra surface area and help improve thermal transmission.

Innovative Technique 3:
The 92mm PWM fan is held in place on the aluminum fins of the Xigmatek HDT-S983 heatsink with four vibration absorbing rubber mounting posts. These fit through the standard screw holes in a vaneaxial fan frame, and keep the fan elevated away from the metal. If the fan motor happens to develop vibrations down the road, the rubber 'shock absorbers' can reduce that from becoming noise.

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is used, and the parameters under which the tests are conducted. Now let's move forward and take a closer look at this heatsink, its acoustic characteristics, and of course its performance in the thermal tests!