360° View - Auras Shagon ARC-118 Heatsink Information on Frostytech's test methodology is available here.
Auras' Shagon ARC-118 heatsink stands 139mm tall, 101mm wide, 88mm deep. It's 92mm PWM fan spins at 2400-1000RPM and draws power from a standard 4-pin PWM motherboard fan header. Four 6mm diameter copper heatpipes extend from the base up to the top of the 92mm aluminum fin stack. Each aluminum fin measures 0.4mm thick and is spaced 2.0mm apart.
The bottom fin is elevated 36mm above the CPU socket for clearance. Heat pipes are positioned 7mm on center at the base plate and rise up 71mm and 51mm apart. The base incorporates an 8.5mm thick aluminum section to provide support for clamping.
The usable area of the Shagon ARC-118 heatsinks's base is 38x42mm in size. Looking from the top down, the fan plenum is 8-11mm. Heatpipes are generally positioned in the path of highest airflow from the 92mm fan.

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 exposed heatpipe base of the Auras Shagon ARC-118 heatsink has a smooth sanded surface texture. Surface roughness is approximately 32 microinches. The base is flat in the axis parallel to the direction of the heatpipes and slightly uneven in the opposite axis, indicating a less than ideal heatpipe-to-aluminum swaged joint. One outer heatpipe is slightly higher than the remaining three, but this varies across the base plate.

Next up, Frostytech heatsink sound level measurements...