Sapphire HD3870 512MB TOXIC Edition Review

The Inner Workings of Vapor-X Technology

Vapor-X technology is basically a patented Sapphire technology which is used to cool off the GPU core using a vapor chamber. In a nutshell, a vapor chamber cooler will hold water which is vaporized by the heat generated by the core. This vapor will carry the heat to a condensation wick which will then be dispersed through the top plate and transported back to the base plate where the process repeats itself. In this section we will look a bit closer at how Sapphire has implemented this technology to efficiently cool RV670XT core on their HD3870 Toxic.


Here we have a breakdown of the different components which go into the manufacturing of a vapor chamber. Let’s start at the bottom with the lower cover which is in this case the copper base-plate that makes direct contact with the core. From there we have the vaporization wick which is placed directly above the GPU core and sits on the lower cover so the water contained therein will quickly vaporize and make its way through the chamber to the condensation wick. The condensation wick is placed in direct contact with the upper cover which is also copper in order to disperse the heat generated as the water vapor condenses on the condensation wick. As we saw, nearly the entire top cover has aluminum fins on it in order to quickly move away the heat. Finally, we have the transportation wick that is used to transport the condensed water back to the vaporization wick.


In order for this method to be effective, the entire chamber needs to be sealed and put under vacuum. This is due to the fact that water vaporizes much easier in an environment with extremely low air pressure. Thus, it is very important that a vapor chamber cooler is well made without any manufacturing defects or the air pressure within the vapor chamber will decrease and this will result in lowered heat dissipation capabilities.


If all of this explanation was a bit too much for you, Sapphire provided us with a handy diagram that shows the process which the heat takes in its journey through the vapor chamber. Something to note here is because this is water vapor in a vacuum, it will spread evenly over the whole condensation wick instead of accumulating all on one spot directly above the core.


So after all of that information, what are the claimed benefits of a vapor chamber-based heatsink? Here you can see the main benefit is that the heat evenly spreads over the top plate which makes it much easier to disperse via more traditional methods. Sapphire has chosen to use aluminum fins which are cooled directionally by a single fan so this should result in quick heat transfer.

According to the documentation we have from Sapphire, a vapor chamber has 50% less thermal resistance than copper while having TWICE the heat conductivity. Add to that the fact that is it omni-directional (due to the low air pressure) whereas copper sticks to the old “heat rises” mantra and this looks to be a hell of a technology.