The XIGMATEK HDT-SD964
Topside, there isn't much going on. The fins are straight as an arrow and the heatpipes are pretty conventional.
A look at the side shows the same thing; many of the newer heatsinks we have looked at bend the fins to raise surface area, but the HDT-SD964 uses perfectly flat fins.
A look at the other side; now with the fan installed. I really like the way XIGMATEK mounts their fans. The rubber piece acts as a buffer between the fan and the fins eliminating all noise caused by vibration. It is best to mount the fan before installing the heatsink to the motherboard, since you will need to pull the rubber through the fan.
Here we see the front of the fan after being installed on the heatsink.
Here we see where the action is really at. The base of the cooler places the heatpipes where they come in contact with the processor directly. This eliminates the need for heat to be passed through a layer of metal before being taken to the fins.
The top side of the base has four tracks cut for installing the cooler to AMD processors. At first I thought it would be possible to mount the cooler either way, but the heatpipes get in the way of mounting the cooler one direction.