The unique construction of the CNPS3100G is shown in this picture of the center portion. In the manufacturing process, between 50-60 individual fins are tightly binded together with a vice, then smoothly milled on the base to provide the perfect surface for a processor to transfer heat.

There is no fan mounted directly on the heatsink, but rather a 80mm fan is mounted to the case with a metal bracket. The end result is that the CNPS3100G can use a lower RPM, larger 80x80x25mm fan to move air over the heatsink's fins.

The fan attachment measures 17.5x17x4cm and screws onto the case by using the first three slot card screw positions. The 25cm long fan wire plugs directly into the motherboard to offer RPM monitoring. A special "noiseless" adapter cable drops the voltage going to the fan to offer even quieter operation. The fan is a 12V, 0.25A "power cooler" brand.

Also included in with the heatsink are a small syringe of thermal grease, a set of screws to attach the fan to the case, and the stainless steel clip used to hold the CNPS3100G in place.

We tried the heatsink for fit on both a socket based motherboard, and via a slocket on a slot 1 mother board. In each case there was no problem with fit. Since the fan mounts above the heatsink there are never really any issues with it being in the way (unless say you are using a mini-tower which has the power supply positioned above the cpu). The heatsink itself is 65mm in height, so as long as your RAM slots are not too close to the CPU there shouldn't be a problem with fit when using a socket 370 to slot 1 adapter. The VP6 will have a problem with the fins of one of the heatsinks touching the back of an AGP card if one is present. Some bending or some insulation can quickly resolve the issue however.

With the fan mounted in place above the heatsink there remains about 1cm worth of spacing for good air flow about all the fins. Depending on the case you use, and the motherboard in your system the fan may be directly above the heatsink, or off to one side. Our test setup was just about on center, but so long as the fan is at least partially over the heatsink Zalman claim the any offset will have a minor impact. Let's now check out how the CNPS3100G scored on the Frosty Synthetic Temperature Test platform against a variety of heatsinks you know...

FrostyTech Synthetic Temperature Test Platform:

The FrostyTech Synthetic Temperature Test Platform consists of an aluminum block heated by a 120V 250 Ohm precision resistor producing 50W of heat. That heat is transmitted to the heatsink via the aluminum block and up through special copper die templates with thermistors embedded directly in them.

A temperature reading for a particular heatsink is taken once the temperature stabilizes in the copper die template. Since each of the die templates have the surface area of either a silicon topped or heatspreader-topped processor the flow of heat to the base of the heatsink accurately mimics a real life configuration.

Shown with the copper die template for a silicon-topped processor, the synthetic heatsink test apparatus awaits a coating of silver-based thermal compound and the Zalman CNPS3100G FHS heatsink. A slightly larger copper die template was used to test the effective cooling ability of the CNPS3100G atop a heatspreader-based processor like an overclocked PGA Celeron processor.