ATI is working on the 4790 which is based on the high-end chip RV790. This card will offer a better performance than a HD 4770 and a better power output than a HD 4850. It's a mystery to us why AMD does not call this card a HD 4860 then since HD 4790 will probably confuse customers, provided that the reports are true.
The specifications of the card : RV790 chip which means 800 stream processors, 512 MiByte GDDR5-VRAM with 256 Bit. The clock rates will be 600 MHz for GPU and real 800 MHz (effective 3,200 MHz) for graphics memory.
The pricing of the Radeon HD 4790 has not been published yet but it might be between HD 4850 and HD 4870.
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