Well if you look at the two they are almost exactly the same. They both utilize heat pipes with fins to dissipate the heat. They allow you to add a fan of your choosing (however the XP-120 does not come with a fan). I belive the biggest difference between the two is the mounting apparatus used. The 120 uses clips to mount onto a 775 board (not sure about the 939 setup) whereas the BT uses nuts.
Originally Posted by OC'ing Noob
There are only so many types of heatsink designs one can come up with, so the first design of similar heatsinks can be considered as a reference. I think what Chimera means is that both of them uses a heatsink mounted by heatpipes to improve heat transfer and if XP-120 increases, then BT used XP-120 as a reference to build their own design.
So far, the only type of HS I can think of as truly unique, is the Zalman CNPS-9500.
Beat me to it. That's exactly what I was saying, and yes, the 9500 is by far the most unique HSF to date.