360° View - Coolermaster Hyper N520 Heatsink Information on Frostytech's test methodology is available here.
Looking at the Hyper N520 head on it's clear how much the two 92mm fans are offset. A single 3-pin motherboard header supplies power to both fans, and each rotates at a fixed 1800RPM. Coolermaster allow 40mm clearance below the lower fan for nearby motherboard components.
Coolermaster's Hyper N520 heatsink stands 142mm tall. Its raw aluminum fins are press-fit over five 6mm diameter copper heat pipes lined up in a row. Each aluminum fin measures 0.3mm thick. Fins are spaced 1.5mm apart. The copper part of the base is 3.5mm thick, total base thickness is 11mm.
It's difficult to see, but the center area of the aluminum fins have holes punched out to promote some degree of vertical air movement. The Hyper N520's copper base is machined flat and measures 37x37mm square. The four holes are for the CPU mounting plates to attach with. Each of the five 6mm diameter copper heatpipes runs the full height of the 142mm tall heatsink.

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 Coolermaster Hyper N520 heatsink has a machined base with a surface roughness of approximately ~8 microinches. The base is perfectly flat in both axis. Next up on Frostytech, acoustic measurements.