eTeknix came across leaked details of NVIDIA's GM204, an upcoming chip believed to be the direct successor to the GK104 that currently powers the GTX 770, GTX 760, GTX 680, GTX 670 and GTX 660 Ti series.
Like the current model, the GM204 will reportedly use a 256-bit memory bus. The memory amount will likely be 2GB GDDR5 memory with some custom models coming with 4GB GDDR5.
The GM210 is expected to replace the GK110 and the GM204 is expected to serve the mid-end. Other than that details about the GM204 are sparse, some sources say the chip may be made on a 20nm process while others claim it's going to be 28nm to save costs and because 20nm isn't mature enough.