Link of all the charts
Tom's Hardware was quick to take down all of these quickly. But a few keen eyes were able to capture them before being taken down.
Overall, the GTX 680 seems to be about 10%-20% faster than the 7970, all while consuming less power and producing less heat. Now remember, this is Nvidia's GK104 GPU, and not the GK110 (which is supposed to their highest end and probably going to be named GTX 780). I don't know if Nvidia plans on releasing the GK110 chip this year at all. But given the GK104 GPU is 20% faster than the 7970, I am guessing the GK110 chip will be 40% faster. That will be pretty cool.
The rumored price of the GTX 680 is said to be $499. I would say this is overpriced given that it's actually Nvidia's mid range GPU. I wonder how much they are going to charge for the GK110 graphics cards (GTX 780).
Seeing this graphic card also is nearly in pair with dual GPU like 6990 and GTX590. I can not imagine how fast GTX690 and 7990 will be.