XFX Radeon HD 7790 Black Edition 1GB Video Card Review
 

The latest AMD Radeon HD 7790 GPUs feature a revised AMD PowerTune Technology implementation, with 8 states, more shader units compared to the versions and higher frequencies. The XFX Black Edition implementation comes with raised speeds from the factory and an enhanced Double Dissipation cooling system for a good efficiency, while maintaining low noise levels.

http://www.madshrimps.be/articles/article/1000430/