360° View - DeepCool Gammaxx 400 Heatsink Information on Frostytech's test methodology is available here.
DeepCool's Gammaxx 400 heatsink ships with a 120mm PWM fan. Additional wire fan brackets are supplied to attach a second fan on the rear of the heatsink. The 162mm tall cooler has four 6mm diameter copper heatpipes which are exposed at the base of the cooler to make direct contact with the processor IHS. Each aluminum fin measures 0.4mm thick and is spaced 2.0mm from the next. The bottom-most fin is elevated 32mm above the base for motherboard clearance (the first full-width fin is 62mm above the CPU).
The four 6mm diameter copper heat pipes are set into a thin 10.5mm thick aluminum base plate and exposed at the base. The base pate provides support for the mounting brackets which screw into it. Each springy wire fan clip which has two small thumb tabs to make fan removal easier (a feature we REALLY appreciate after testing hundreds of heatsinks where the fan clips are near impossible to get out).
The exposed heatpipes on the base of the Deepcool Gammaxx 400 create a usable surface area of 35x42mm. Looking at the top of the heatsink, we see the heatpipes are 5.5mm from each other and 60mm across so as to be in the highest airflow region.

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 exposed heatpipe base of DeepCool's Gammaxx 400 heatsink has been machined flat, with a surface roughness of approximately ~16 microinches. The base is perfectly flat in both axes. It's always nice to see thermal solutions makers read these reviews and improve on their coolers shortcomings.

Up next, heatsink sound level comparisons....