FrostyTech posted a review on the nPowerTek NPH SF775-2 Heatsink
The nPowertek SF 775-2 heatsink features a body made of copper fins which have been wrapped around a central copper slug. The copper column makes contact with the actual CPU core, and the heatsinks' 136 copper fins radiate the heat out into the surrounding air. Anyway you slice it, there is a lot of copper in this puppy. Does a half kilo of guarantee amazing thermal performance? Nope, not by any stretch; it's how that copper is used, not how much is crammed in there. Of course, we'll reserve judgement until the thermal test results come in... a little later in FrostyTech's review.nPowerTek NPH SF775-2 Heatsink Review