360° View - Zalman CNPS11X Extreme Heatsink Information on Frostytech's test methodology is available here.
The 120mm PWM fan spins at 1000-1950RPM and draws power from a standard 4-pin PWM motherboard fan header. It is backwards compatible with 3-pin connectors. Each of the five copper heatpipes are 6mm in diameter and extend from the base up to the top of the 155mm tall heatsink. Each nickel plated aluminum fin measures 0.2mm thick and is spaced ~1.0mm apart.
The Zalman CNPS11X Extreme heatsink stands 155mm tall, the tower is 96mm wide and the first fin is elevated 38mm above the CPU socket. Heat pipes are positioned 7mm on center at the base plate and rise up from 35-115mm apart. The base incorporates a 13mm thick nickel plated copper heatspreader which also provides support for clamping.
The usable area of the CNPS11X Extreme's base is 40x38mm in size. Looking from the top down we see the large V-shape the fin towers present to the exhaust airflow from the 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 base of the Zalman CNPS11X Extreme heatsink is generally flat in one axis and very slightly convex in the opposite, mostly just over the center. The copper baseplate has been machined but the nickel plating on top of that gives the surface a glossy finish that is very smooth. Surface roughness is at or better than ~8 microinches, which is excellent.

Next up, Frostytech heatsink sound level measurements...