360° View - Scythe Big Shuriken Heatsink Information on Frostytech's test methodology is available here.
The 12x120x120mm fan is held in place on the Scythe Big Shuriken heatsink with wire clips. The fan spins at 900-1600RPM, and is powered by a standard 4-pin PWM fan header. With the fan removed we can see the large but very thin aluminum fin array. The nickel plated aluminum fins measure 0.3mm thick and are spaced 1.5mm apart.
The body of the Scythe Big Shuriken heatsink is only 10mm thick, and four 6mm diameter copper heatpipes are soldered along the bottom edge. The stacked aluminum fins are less restricted at the edges by the copper heatpipes, so air exhausts down and out towards adjacent motherboard components. Below all of this is the extruded aluminum base cap the heatsink mounting clips lock into.
The four heatpipes are soldered between the aluminum extrusion and a 2mm thick nickel plated copper base plate. The base measures a broad 38x50mm, and has a smooth polished finish. The base is generally very flat.

Base Finish and Flatness

Flipping a heatsink over to inspect the business end is often a simple indicator of overall cooler quality. More practically speaking, a heatsink is in many ways only as effective as the contact it makes with the processor - the flatter and smoother the better. Base finish is one of the criteria that Frostytech measure in the course of evaluating heatsinks, and it involves two distinct aspects. Surface Finish is the first; this is calculated with the aid of Surface Roughness Comparator that has a cross section of common machine surface finishes and their numerical surface roughness equivalents in microinches. The second is Surface Flatness. This is tested with an engineers straight edge or proven flat surface, in two axis.

The base of the Scythe Big Shuriken heatsink has been stamped from a polished sheet of 2mm thick copper, and nickel plated. The base is smooth, with a surface roughness of ~8 microinches (considered excellent). It is generally flat in both axis but not perfectly so.

Next up, sound measurements to determine how loud the Scythe Big Shuriken heatsink is when operating at stock speeds.