360° View - Zalman CNPS9900DF Heatsink Information on Frostytech's test methodology is available here.
The front 120mm fan spins at 1000RPM and draw power from a single 3-pin motherboard fan header, the middle fan is a 135mm unit, PWM controlled and operates at 1400-900RPM. Each of the three composite wick copper heatpipes are 6mm in diameter and extend from the base up and around the cooling fins, then back to the base. Each nickel plated copper fin measures 0.2mm thick and is spaced ~1.5mm apart.
Zalman's CNPS9900DF heatsink stands 154mm tall, the fin area is 136mm wide and the first fin elevated 32mm above the CPU socket. One heatpipe runs around the front set of cooling fins, two heatpipes around the rear set of fins. The base incorporates a 4.5mm thick nickel plated copper baseplate to spread heat more evenly from multi-core processors to the heatpipes.
The nickel plated copper base of the Zalman CNPS9900DF heatsink measures 35x35mm in size. Looking from the top down we can see the front 41mm thick and rear 33mm thick fin stacks. The translucent fans are softly illuminated with blue LEDs.

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 base of the Zalman CNPS9900DF heatsink is flat in one axis and very slightly convex in the opposite, mostly towards the edges. The nickel plating adds durability to the unit as a whole, but Frostytech generally prefers this coating to be machined away from the processor mounting surfaces for the sake of optimal thermal conductivity. Surface roughness is at or better than ~8 microinches, which is excellent. The base finish is smooth, mirror like.

Next up, Frostytech heatsink sound level measurements.