FrostyTech posted a review on the Thermalfly I75DUH Bifurcated Fin Heatsink

The second Thermalfly heatsink to cross the FrostyTech test bench this week is the new I75DUH cooler - a socket 775 model with straight, ultra thin bifurcated fins. This is a low-profile cooler for Intel Pentium D and Core 2 Duo processors, and given the pedigree of this thermal design, it should do pretty well by all accounts. Of course we'll have to wait for the thermal results before drawing any final conclusions... Thermalfly's I75DUH heatsink is equipped with a 96mm fan that rotates as lackadaisically as 500RPM, yet it can scale up to 2300RPM when the needs demand. The 4-pin PWM is controlled by the BIOS on compatible motherboards, and when it's installed on motherboards that don't support PWM CPU fans, it rotates away at full speed. At full tilt, the heatsink produces a little more than 48 dBA.

Thermalfly I75DUH Bifurcated Fin Heatsink Review