Thanks to it's unique cooling solution, the OCZ Reaper HPC memory modules are very distinctive in appearance which sets them apart from the masses of memory modules making use of flat heatspreaders. The black heatspreaders and copper heatsinks give the Reaper a very slick look, although it also makes it nearly twice the height of most memory modules. While there are a couple of manufacturers offering after-market memory cooling solutions that make use of heatpipes, OCZ is the only memory manufacturer to use such a design. OCZ calls their cooling solution the Heat Pipe Conduit, abbreviated to HPC.
The Reaper Heat Pipe Conduit system consists of a large aluminum heatspreader attached to an aluminum fin array by a copper heatpipe. The aluminum fin array is basically a thin and long heatsink. The entire assembly resembles an elaborate handle, not unlike what you might see on a closet or dresser, although the space between the heatspreader and the fin array is too small to fit your fingers through. In order to increase the surface area, which improves heat dissipation, the aluminum fin array that constitutes the "grip" of the handle has a large number of notches cut into it. When viewed as a cross-section, the "grip" is actually in the shape of a X. This shape was chosen to further increase the fin array's surface area.
Reaper HPC PC2-8500
Reaper HPC PC2-6400 EB
The heatspreader, which is clamped to both sides of the memory module, has a number of channels cut into its otherwise flat surface, increasing its surface area. On one side is a shiny badge proudly displaying the OCZ logo. The other side of the module is completely plain except for the afromentioned channels cut into the heatspreader and two screws, which secure the heatspreader assembly in place. This side of the module also has a sticker in the upper left corner which specifies the model, speed and timings for the module.
The HPC system works in two stages. First, the heat generated by the memory modules is absorbed by the heatspreader. The heatspreader does exactly what its name implies and spreads the heat accross its surface. The copper heatpipe then moves some of this heat away from the heatspreader to an aluminum fin array where the heat is dissipated into the surrounding air. This design uses the same basic principles used by other heatpipe systems and in theory it should greatly increase the cooling system's thermal capacity.
Remember that heatpipes are used in cooling applications to transport heat
from one point to another, quickly and relatively efficiently
. Heatpipes, on their own, don't have any noteworthy cooling capabilities. In this, as well as many other heatpipe systems, the heatpipe is used to connect a primary heatsink to a secondary heatsink. Due to its high efficiency, the heatpipe effectively joins the two heatsinks together, increasing the total surface area that can be used to dissipate heat. A larger surface area means the heatsink can dissipate heat quicker and handle larger thermal loads.
It's for this reason that you can't simply slap some heatpipes onto a heatsink and expect it to work effectively. The heatpipe needs to be well integrated so it can transport as much of the heat from the heatspreader to the fin array as possible. This, unfortunetly, is where the HPC's design falters. The heatpipe in the HPC assembly is simply tacked on to the top of the heatspreader. From this position, it will only have access to a small fraction of the heat collected by the heatspreader. It would have been much more effective if the heatpipe was attached to either side of the heatspreader near the center, right above the memory chips, where the heat is most concentrated.
The current position of the heatpipe reduces its effectiveness since it can only reach the relatively small amount of heat that rises to the top of the heatspreader. While this doesn't make the heatpipe assembly useless, it does mean that it won't reach its full potential.
Overall, the Reaper HPC is very well constructed. When we first saw images of the Reaper HPC, we
n order to seat the memory modules, you would need to apply a significant amount of pressure on the heatpipe assembly which may weaken it, causing it to break after several installs. After several dozen cycles of installation and removal during benchmarking, the assembly remains securly affixed. We never experienced any give or flexing while installing or removeing the modules. We're happy to report that our initial fears were unfounded and the heatpipe assembly is well constructed and very sturdy.