Rumor: Nvidia GeForce GTX 680 to arrive in February - CorePC.com (Hardware Specialist)

      A rumor on the Chinese forum ChipHell.com, has it that Nvidia will release the GTX 680 earlier than the March time-frame in response to the release of the AMD 7970 graphics chip. The GTX 680 will be based off of Nvidia's new 28nm Kepler archatecture. The 7970 is currently the fastest single chip in the world, while Asus's Mars II Limited Edition Dual GTX 580 card is arguably the fastest single graphics card in the world.

http://www.techspot.com/news/47092-rumor-nvidia-geforce-gtx-680-to-arrive-in-february.html

http://www.maximumpc.com/article/news/nvidia_geforce_gtx_680_may_launch_ahead_schedule