The Fans:

There are 52 fins in total on the CNPS6500B-AlCu model, and each fin is about 53x68x0.5mm in size. Altogether the heatsink weighs in at 400grams, making it moderately heavy, but not as much as the full copper version would be. At the circumference of the fins, the tips are spaced roughly 2mm apart for good airflow, and the central copper section helps to spread the heat from the core quickly up to the outer edges of the fan heatsink.

Side B:
To improve circulation, and increase surface area, Zalman have perforated the fins with five 3mm x 41mm slots. A few creeses have been added to the aluminum fins to help make them a bit more rigid, and the tops have also been scalloped. The two bolts which hold the many pieces together are stainless steel, and the side aluminum flanges are used during mounting in the heatsink retention mechanism.

Zalman have always finished their heatsink bases to impeccable standards as far as we're concerned. With the larger 6500 series it is really important not to bang the heatsink down on a hard surface or a few of the fins might get dislodged by a 0.25mm or less which could cause a problem during installation. Generally speaking, only a very small amount of good quality thermal compound should be applied. The entire base area measures 56x83mm.