http://www.techpowerup.com/159009/Ge...-225W-TDP.html
For those of you less technically inclined, AMD's HD7000s and Nvidias 600 series GPUs are being built with a 28nm process as opposed to the previous generation's 40nm process, this results in equal performance for less power, or better performance for equal power (whichever way you want to look at it). Basically, it's more efficient.
Now, while having the same power draw as the 6970, the 7970 managed to beat out Nvidia's 580 by 10% or more. So, if Nvidia's new 680 (225w TDP), despite being built with the 28nm process, is going to draw nearly as much power as their 580 (244w TDP), what does that say about it's performance?
I can't wait.
Edit: Upon further research, the GK104 might actually be the 670 (to the 570's 219w TDP), rather than the 680, which implies even grander things.