360° View - GlacialTech UFO V51 Silent Heatsink Information on Frostytech's test methodology is available here.
The twin 92mm fans on the GlacialTech UFO V51 Silent heatsink spin at 1600RPM each, and a single 3-pin motherboard header provides power to both. With the fans and bulky plastic shroud removed we get a better look at the working end of the UFO V51 Silent heatsink. Two 6mm diameter heatpipes on the outer ends, two 8mm diameter heatpipes at the center. The aluminum fins are scalloped on both leading and trailing edges and measure 0.2mm thick. Fins are spaced ~2.0mm apart.
The GlacialTech UFO V51 Silent stands 136mm tall and is 165mm wide. Its raw aluminum fins are press-fit over the four nickel plated copper heatpipes. The bottom of the heatsink is elevated 45mm above the base for adequate motherboard component clearance. The copper heat spreader that caps off the heatpipes is 2mm thick.
The copper base plate on the GlacialTech UFO V51 Silent heatsink is nickel plated and polished, it is generally flat in both axis. The footprint is 50x48mm, with the two 8mm diameter heatpipes soldered towards the center and the 6mm diameter heatpipes positioned towards the outer edges where there is generally less heat (given the size of an Intel IHS being 28x28mm). The slot through the top of the aluminum base cap is for the mounting bracket Glacialtech supply.

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 GlacialTech UFO V51 Silent heatsink has a 2mm thick, nickel plated copper base with a surface roughness of approximately ~8 microinches. The base is generally flat in both axis, but not perfectly so.