360° View - Intel stock Core 2 Duo E4400 Heatsink Information on Frostytech's test methodology is available here.
The stock Intel Core 2 Duo E4400 heatsink is built with an 85mm diameter fan that spins at speeds an 2000RPM. The speed of the seven-bladed Pulse Width Modulation (PWM) fan is controlled via the BIOS. Power is supplied by the 4-pin PWM fan cable which connects to a standard 3-pin or 4-pin motherboard fan header. With the fan support structure removed, the unique design of Intel's stock Core 2 Duo E4400 heatsink is clearly visible. The aluminum 'donut' measures 90mm in diameter, with 2.5mm of aluminum wrapping around the aluminum slug, and then 24mm long aluminum cooling fins extending out. Each aluminum cooling fin is 1.0mm thick and spaced 2.0mm at the base, 1.5mm apart at the tip. The bifurcated tips are each 0.5mm thick to allow air to easily pass through.
The body of the stock Intel Core 2 Duo E4400 heatsink stands exactly 32mm tall, with an overall height of 63mm. The four push-to-lock plastic clips lock directly into the 4mm motherboard mounting holes which surround the LGA775 processor socket. To release the heatsink from the board, the upper portion of the clip is rotated 90 degrees and pulled upwards. The heatsink then pulls free of the motherboard. The fan support frame locks onto the aluminum portion of the heatsink with a couple slashes cut into the side of the fins. The fan frame is held in tension, so vibration and rattling shouldn't be an issue. Air is exhausted outwards from the cooling fins, where it can then be used to cool adjacent board-mounted components.
The aluminum base of the stock Intel Core 2 Duo E4400 heatsink is 29mm in diameter where it makes contact with the processors integrated heatspreader (IHS). The heatsink ships with a thin grey pad of thermal interface material pre-applied. The aluminum base is machined perfectly flat, and is smooth.