360° View - Spire SP741B3 Heatsink Information on Frostytech's test methodology is available here.
	The Heatsink Fan: The 90x90x25mm fan is UV-light reactive with a seven-bladed impeller that rotates at 2400RPM, producing in the region of 41CFM. It draws power from a standard 3-pin motherboard connector that supports RPM monitoring. The fan wires are sheathed to reduce cable clutter.
	Heatsink Top: The 90mm fan is held in place on a slim aluminum fan support. As you can see, the footprint of the fan is somewhat larger than the actual copper fin array, leading to the off center positioning. The fan is supported about 5mm above the tips of the copper fins, which have a concave profile.
	Heatsink Side A: From the side we can see ~60 very thin copper fins soldered to the 10mm thick copper base plate. Each fin measures roughly 35mm tall and 40-76mm wide (at base, and at top). The fins are ~0.2mm thick and spaced 1.0mm apart. Note on the left hand side how the 90mm fan goes slightly past the copper fins.
	Heatsink Side B: The four copper heatpipes are equally spaced and slightly inset into the thick copper base. Each 5mm diameter heatpipe extends up about 30-35mm, and goes fully through all the thin copper fins to aid in heat transmission. The springs help ensure that equal pressure is applied on the CPU when the Spire Diamondcool II is installed.
	Heatsink Base: The copper base extends into mounting supports at either end. The 10mm thick copper plate supports the spring tensioned screws easily without sign of flexing. The overall dimensions of this massive copper slab are 40 x 97mm, of which only a 37.5 x 37.5mm square area actually makes contact with the IHS of the AMD Athlon64 processor. The base has a sanded finish, and is pretty flat in the X-axis, and slightly wavy and concave along the Y-axis (top-to-botton in the picture). The metal has a surface roughness of ~63 microinches.