360° View - X2 Products Eclipse IV Heatsink Information on Frostytech's test methodology is available here.
The Eclipse IV heatsink ships with two rubber bumper fans measuring 122x122x27mm that draw power from a single 4-pin motherboard fan header thanks to the supplied Y-splitter. The bifurcated fin towers measure 63mm wide by a depth of 74-57mm. Each tower each stands 108mm tall. The six 6mm diameter heatpipes are evenly spaced through the fin stock, but closely spaced at the base plate. The nickel plated aluminum fin edges have a fine saw-toothed profile. Note the 4mm space down the center of the heatsink.
The X2 Products' Eclipse IV heatsink stands 160mm tall; the bottom most aluminum fin is elevated 40mm over the CPU. Each fin measures 0.4mm thick and is spaced 2.0mm apart. The heatpipes are spaced 75mm apart so the heat they conduct is 'dumped' into the region of cooling fin in the direct path of the highest airflow from the fans.
The base of X2 Products' Eclipse IV heatsink measures 40x40mm in size. The copper base plate is 2-to-5mm thick. The six 6mm diameter copper heatpipes are soldered to the copper base plate and aluminum base cap, the whole kit and kaboodle is then nickel plated to prevent surface oxidation. From this angle we can clearly see the slots for the springy wire clips to hold the 120mm fans in position, on either side of the 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 engineer's straight edge or proven flat surface, in two axes.

The nickel plated copper base of the X2 Products' Eclipse IV heatsink is perfectly flat in one axis and very slightly concave in the opposite. The metal has been machined very smooth and nickel plated, so surface roughness is ~4 microinches or better, which is excellent.

Next, heatsink noise level measurements and then it's on to the thermal test results.