During his keynote address at GTC 2013, NVIDIA CEO Jen-Hsun Huang revealed the roadmaps for its graphics processors and Tegra chips. Both roadmaps introduced the successors that will replace the incumbents Kepler and Tegra 4 respectively.
The next generation Maxwell GPU will feature the new "unified virtual memory" where this shared memory space is accessed by both GPU and CPU. Volta, the successor to Maxwell, will feature a groundbreaking technology called "Stacked DRAM" where the video memory chips co-exist on the same silicon strata as the Volta GPU to increase its memory bandwidth to 1TB/s. As a point of reference, the memory bandwidth of the GeForce Titan GPU is 288.4 GB/s while the GeForce GTX 690 has a collective memory bandwidth of 384.4 GB/s (192.2 GB/s per GPU). According to CEO Jen-Hsun, holes had to be drilled through the DRAM layers and allowing them to be stacked together on the same silicon strata as the Volta GPU.