Hexus.net has the scoop on a new Radeon HD4890 from Sapphire that runs at an astonishing 1,000MHz core, compared to the normal 965Mhz of their competitors.  Using their VaporX heatsink technology, it has an “effective” 4200Mhz memory clock.  They plan to officially launch it next week.

Sapphire Plans Atomic HD 4890 With 1000MHz Core Clock – Expreview.com.