What makes this heatsink so special likes at the heart of the central cylinder in the extrusion. Unless you take off all of the hardware and then physically drill, or hack-saw the cooler into two pieces you won't even be able to see it. For that matter why would you want to?

As was shown on Hardocp.com, and Overclockers.com, the center of the ThermoEngine has a portion drilled out and left hollow. Within that chamber is speculated to be a substance which is sealed in by a thick aluminum plug. The top of this plug is visible if you look closely at the top of the heatsink with the fan removed.

What lies beneath this hefty aluminum stop-gap is what reportedly helps to make the ThermoEngine one of the best performing heatsinks we've seen.

For a minute lets make two assumptions. A.) there is an unknown substance in the central chamber. B.) there is nothing in the central chamber.

Our best explanation of assumption A) would be that the speculated substance in the empty chamber allows it to act as a large integral 'heat pipe' of sorts which helps transfer heat from the base of the heatsink more evenly up the entire 42mm worth of fins. Since there has been a bit of confusion on this point, let me just reiterate that according to the images we've seen of the internal workings of this heatsink it doesn't appear to have a sintered metal coating on the chamber walls, which would be indicative of a true heatpipe.

Looking at assumption B) for a moment, the empty chamber is there to serve some thermal purpose. Generally, a manufacture will not go the expense of drilling and then plugging and sealing a hole unless that cost is justified. Whatever the physics are behind the empty space, there should be an equivalent return thermally.

The end goal of either assumption of course is to ensure the efficient use of all the surface area on the heatsink for cooling. As air moves faster at the top of the heatsink, than at the base, this area is valuable cooling real estate.

While there isn't anything particularly special about the clip, I'd have to say it may be one of the more complicated designs we've seen.

It works very well at holding the heatsink securely to the CPU with just the right amount of pressure (about 20lbs according to Thermosonic). Unlike other heatsink clips the angle of the heatsink when it is being clipped into place on the processor is very shallow so there is less concern about chipping the corner off the silicon.

Let's take a look now at how the ThermoEngine compared to the other heatsinks that were tested out on our venerable Frosty Synthetic Temperature Test platform...