Vapor X runs cooler thanks to a better and bigger Fan and placed in the center of Card
It's not about fan and position....
Vapor Chamber Technology is based on the same principles as heatpipe technology. A liquid coolant is vaporised at a hot surface, the resulting vapor is condensed at a cold surface then the liquid is returned to the hot surface. The recirculation process is controlled by a wick system.
Sapphire Vapor-X flattens the whole system into a slim chamber - which in the graphics application is mounted in contact with the surface of the graphics chip.
Actually, the coolant is water – but because the chamber is evacuated to a very low pressure, the vaporisation process occurs at a much lower temperature than normal boiling point. The complex wick arrangement inside the module controls the flow of water and water vapour so that the system can be used in any orientation.