360° View - Glacialtech Igloo 5710 Plus Silent Heatsink Information on Frostytech's test methodology is available here.
The 100mm fan on Glacialtech's Igloo 5710 Plus Silent heatsink rotates at 1300RPM by default. Power is supplied by a standard 3-pin motherboard fan header. The Igloo 5710 Plus Silent heatsink stands 139mm tall, 100mm wide. Three 6mm diameter copper heatpipes are used to conduct heat energy from the base to the 95mm tall section of raw aluminum cooling fins above. Notice how all three heatpipes are arranged in a line, rather than staggered by 5 or 10mm.
Each aluminum fin on the Igloo 5710 Plus Silent heatsink is 0.3mm thick and spaced 1.5mm apart. There is no plenum behind the fan per say, but the scalloped edge on the fins likely has a similar effect. Clearance below the lowest fin is 32mm to the CPU.
Three 6mm diameter copper heatpipes pass through the aluminum fins. At the base the heatpipes are packed 4mm apart, flattened slightly and soldered to the 2mm thick copper base plate. The base measures 32.5x34mm in size and ships with a pre-applied patch of thermal compound.

Next up Frostytech measures the sound output from the Glacialtech Igloo 5710 Plus Silent heatsink with its fan running at full speed...