OCC has published a article on the NVIDIA GeForce GTX Titan

Architecturally the GTX Titan is using the by now familiar Kepler architecture first shown when the GTX 680 was released just shy of a year ago. This time however, we get the full GK110 version of the silicon. Packed full of 7.1 billion transistors using a 28nm process, the GTX Titan is equipped with five Graphics Processing Clusters, 14 streaming multiprocessors each with 192 CUDA cores (2688 total), a total of 224 texture units, 48 ROPs, and an impressive 6GB frame buffer running through a 6 x 64 (384) bit bus to improve high resolution gaming not just now but into the future. Clock speeds for the GTX Titan are 837MHz on the core with a GPU Boost 2.0 clock of 876MHz as long as the core runs within both temperature and power limits. The 6GB of GDDR5 comes with a 6008MHz (4 x 1502MHz) clock speed for improved memory bandwidth. When you get to the end of the rainbow you are left with the supposed most powerful single GPU card currently in production.