360° View - nPowertek NPH-1366-140HC Heatsink Information on Frostytech's test methodology is available here.
The 95mm 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. The extruded aluminum which surrounds the heat column is 90mm in diameter. The thermal path includes 3mm of aluminum and a ~26mm bifurcated cooling fin. Each fin is 0.8mm thick and spaced 1.0mm apart at the base. The tips of the bifurcated fins are 0.5mm thick, 1.5mm apart.
The LGA1366 nPowertek NPH-1366-140HC heatsink stands 72mm tall. Air is exhausted downwards from the fan with a clear plastic fan shroud.
The copper base of the nPowertek NPH-1366-140HC heatsink is 37mm in diameter where it makes contact with the processor integrated heatspreader and at least 6mm thick. The base is perfectly smooth and flat.

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-1366-140HC heatsink has a smooth machined finish which is flat in both axes. Under oblique light the grain of the copper partially visible, 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!