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 Vortex Plus heatsink has a surface roughness of approximately 32 microinches, which is considered good. The base itself has a sanded finish and is very slightly convex in the direction of the heatpipes, very slightly concave in the opposite axis. The degree of curvature isn't that significant, but it's enough to notice when held up to an engineers straight edge. The copper and aluminum parts are flush on the unit Frostytech tested.

Next up, acoustic noise measurements and then it's onto AMD and Intel thermal test reports on Frostytech!