360° View - Thermalfly I75DUB Heatsink Information on Frostytech's test methodology is available here.
	The Heatsink Fan: The Thermalfly I75DUB heatsink is built with a 112mm diameter fan. The 7-bladed impeller spins at speeds of 900-3600RPM depending on the temperature of the heatsink itself (it is thermally controlled). Power is supplied by a standard 3-pin motherboard fan header. There is an 20mm plenum between the top of the aluminum fins, and the bottom of the fan impeller.
	Heatsink Top: With the fan support structure removed, the unique design of Thermalfly's I75DUB heatsink is apparent. The aluminum slug is 33mm around. The aluminum which surrounds the core is 90mm in diameter, though each side is comprised of 3.0mm of aluminum and ~26mm long straight bifurcated cooling fins. Each fin is 0.8mm thick and spaced 1.0mm apart at the base. The tips of the bifurcated fin are a scant 0.2mm thick, and spaced 1.0mm apart. This has to be among the thinnest extruded aluminum we've seen. The thermistor can be seen taped to the center of the heatsink.
	Heatsink Side A: The body of the Thermalfly I75DUB heatsink 41mm tall, and the heatsink has an overall height of 87mm. The spring tensioned screws attach directly to a rear mounted metal support plate that is included with the heatsink. The lower half of the fan is 92mm round, and at the top 112mm across. Note the two black wires leading to the thermistor.
	Heatsink Side B: The fan support frame locks onto the aluminum portion of the I75DUB heatsink with a couple slashes cut into the side of the fins. The fan frame is held in tension, so vibration and rattling isn't a problem. Air is exhausted outwards from the cooling fins, where it can then be used to cool adjacent board-mounted components. Most socket 775 Intel motherboards are designed to use this source of airflow, and so VRM and chipset heatsinks are often entirely passive.
	Heatsink Base: The aluminum base of the Thermalfly I75DUB heatsink is 35mm in diameter where it makes contact with the processors' integrated heatspreader (IHS). The heatsink ships with a thin grey pad of ShinEtsu thermal interface material pre-applied. The base is machined perfectly flat, and is very smooth. Surface roughness is on the order of ~8 microinches, which is considered excellent. The body of the heatsink is 90mm round.