Sapphire HD 7970 Vapor-X GHZ Edition Review @ OCC
 

Adjusting the voltage any higher than 1212mv would cause a driver crash or hard lock during testing and is where I left the voltage while tweaking to find the highest core and memory speeds. At 1193/1605MHz I have the third best core clock speed of any HD 79XX card I have tested with only the water cooled Powercolor HD 7970 LCS and HD 7970 6GB Toxic pulling off a bigger clock speed. Temperature testing on this card with the voltage increase and higher fan speed showed a 5 °C drop over the baseline result at 60 °C showing that the Vapor-X cooler is easily able to deliver excellent cooling to go along with the gaming performance.

http://www.overclockersclub.com/revi...70_vaporx_ghz/