Sapphire Radeon HD 6850 Vapor-X Review - PAGE 3

The Vapor-X design is a four-part solution comprised of the fan, aluminum array, three heatpipes and the vapor chamber.

The vapor chamber technology is based on the same principles as heatpipe technology, where a liquid coolant is vaporized within a chamber, resulting in the heat being transferred though the chamber via an internal liquid which is then cooled and recycled throughout the chamber. This works in conjunction with three copper heatpipes that extend out of the base in the array, and a centralized 80mm fan.

The coolant inside the chamber is actually solid H20, which has a higher heat capacity and vaporizing temperature than most liquids. This makes it ideal for use within the chamber, and aids the thermal efficiency of the unit. As the chamber is evacuated with very low pressure, the vaporization 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.

The PCB is the same high-quality board used with the HD 6870 Vapor-X, meaning Sapphire has pulled all the stops and included an on-board 10-phase power controller, patented Black Diamond chokes and high quality all Japanese capacitors. Additionally, the PCB uses eight tier-1 HYNIX based memory chips clocked at 1100MHz, and an on-board heat spreader to improve the thermal efficiency of the VRM. Overall the board design is excellent for a mid-range card, which will improve the efficiency, overclocking headroom and longevity of the HD 6850 Vapor-X edition graphics card.

Overclocking:

To overclock the HD 6850 Vapor-X Edition graphics card, Sapphire's TriXX utility was used. The core clock frequency was increased by 20MHz intervals until the card started to display artifacts during operation. At that point the GPU voltage was ramped up to the maximum level since heat wasn't an issue, then the core frequency was pushed even higher. In the end the GPU clock speed reached just under 1GHz, which is impressive for a HD 6850 and a 15% increase over the stock frequencies. The memory also scaled well for this model, but it couldn't quite hit a rating of 1200MHz (4800MHz effective). Still, 1170MHz (4680MHz effective) is nothing to sneeze at.