The Die Size of NVIDIA’s Kepler GK104 chip has been estimated by Expreview. NVIDIA would be launching its Kepler GK104 based GTX670Ti/GTX680 during this month, Several key details were also leaked earlier which you can check out here.
The Die Size of the entire chip is around 40mm * 40mm, Core (die) size is about 17.2mm * 17.2mm, The core area is about 300mm 2. Earlier picture suggested that the Core would be 320mm2 , Still the chip is much smaller than the Tahiti XT 365mm2 .
The GK104 cards would be the first Kepler GPU’s to launch, However these are the Performance Segment cards which are meant to replace GTX560Ti/GTX570. The flagship parts are based on the GK110 which arrive late in Q3/Q4 2012.