Word on the street is that AMD will use the 14nm FinFET process from GlobalFoundries for its processors, while TSMC's 16nm FinFET will be used for GPUs like Greenland.
NVIDIA on the other hand added Samsung to its list of foundries earlier this year, but will continue to use TSMC for the next-generation GP100 "Pascal" series GPUs.
Other clients of TSMC's 16nm FinFET include Apple, Avago, Broadcom, HiSilicon Technologies, LG Electronics, MediaTek and Xilinx.