360° View - Nexus HOC-9000 Heatsink Information on Frostytech's test methodology is available here.
The 120x120x25mm PWM fan from between 800-1500RPM, and is backwards compatible with 3-pin motherboard fan headers. It is mounted with four vibration absorbing rubber posts. The aluminum fins on this heatsink are 0.3mm thick and the fin pitch is a rather wide 1.8mm. A compression fitting is used between the 8mm diameter heatpipes and aluminum cooling fins. It's difficult to see here, but the fins are recessed to provide a 15mm plenum behind the fan.
There is a good 47mm clearance below the Nexus HOC-9000 for things like chipset heatsinks and RAM. The four 8mm diameter heatpipes are nickel plated and make four curves before going into the aluminum fins. Large extruded aluminum sections are mounted onto either side of the Nexus HOC-9000, these help channel airflow downward and can be decorated with the supplied stickers. The cuts in the aluminum base are for the AMD mounting clip. The heatsink stands 128mm tall.
Note the little dimples pressed into the lower half of the aluminum fins on the Nexus HOC-9000 heatsink. These are intended to create turbulence and better transfer heat to the air passing through the fins as it decreases in velocity. The HOC-9000's base is comprised of four 8mm diameter heatpipes which have been flattened into an aluminum base support (11mm total thickness). All heat is conducted via the four heatpipes only, so the wide spacing between the heatpipes is a little perplexing. The base size is 42x35mm.

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 Nexus HOC-9000 heatsink has a lightly sanded base finish with a surface roughness of ~32 microinches. The base is comprised of the four flattened 8mm diameter heatpipes and aluminum support, all of which is 42x35mm in size. the five aluminum spacers are each about 1.8mm wide. Using a straight edge held up against the HOC-9000's illustrates a very slight concavity in both axis - most likely from the sanding step.

Next, let's see how this heatsink handles the heat compared to a selection of the best AMD, and then Intel heatsinks!