360° View - nPowertek NPH-775-115HC Heatsink Information on Frostytech's test methodology is available here.
The 92mm diameter PWM fan spins its 3000-15000RPM and draws power from a standard 4-pin PWM motherboard fan header. The 33mm diameter copper heat column at the center of the heatsink body extends all the way to the base. Each aluminum fin is 0.4mm thick and spaced 2.0mm apart.
The LGA775 version of the nPowertek '115HC heatsink stands 115mm tall. The aluminum fin stack makes up 88mm of that height.
The copper base of the nPowertek NPH-775-115HC heatsink is 37mm in diameter where it makes contact with the processor and 6mm thick.

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 copper base of the nPowerTek NPH-775-115HC heatsink has a smooth machined finish which is very slightly concave. Surface roughness is at or better than ~16 microinches.

Next up, let's see how this heatsink handles the heat compared to a selection of other heatsinks!