360° View - Coolermaster Gemin II M4 Heatsink Information on Frostytech's test methodology is available here.
The 15x120x120mm PWM fan spins at 1600-500RPM and draws power from a standard 4-pin PWM motherboard fan header. Four 6mm diameter copper heatpipes support the thin aluminum cooling fin array, before looping around to the exposed heatpipe base. The fin array measures ~120x82-99mm. Each aluminum fin measures 0.3mm thick and fins are spaced 1.6mm apart.
The Coolermaster Gemin II M4 heatsink stands just 61mm tall, the bulk of the fins are elevated ~37mm above the CPU for clearance. The base incorporates an 10mm aluminum base plate to provide extra support for its metal mounting brackets.
From this side the Gemin II M4 looks like a smiley face. :) The exposed heatpipe base measures 45x45mm in size. Each copper heatpipe has been swaged into the aluminum base block and the surfaces made flush by a light sanding. Surface roughness is on the order of ~32 microinches, which is considered good.

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 engineer's straight edge or proven flat surface, in two axes.

The Coolermaster Gemin II M4 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. The heatpipes and aluminum plate are generally flush to one another.

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