The Oak Ridge National Laboratory has been interested in a successor for their Titan Supercomputer. Sponsored by the US Department of Energy, the new computer will be based on NVIDIA's Volta (GPU) and IBM's POWER9 (CPU) architectures. Its official name will be “Summit”, and it will have a little sibling, “Sierra”. Sierra, also based on Volta and POWER9, will be installed at the Lawrence Livermore National Laboratory.
Image Credit: NVIDIA
The main feature of these supercomputers is expected to be “NVLink”, which is said to allow unified memory between CPU and GPU. This means that, if you have a workload that alternates rapidly between serial and parallel tasks, that you can save the lag in transferring memory between each switch. One example of this would be a series of for-each loops on a large data set with a bit of logic, checks, and conditional branches between. Memory management is like a lag between each chunk of work, especially across two banks of memory attached by a slow bus.
Summit and Sierra are both built by IBM, while Titan, Oak Ridge's previous supercomputer, was developed by Cray. Not much is known about the specifics of Sierra, but Summit will be about 5x-10x faster (peak computational throughput) than its predecessor at less than a fifth of the nodes. Despite the fewer nodes, it will suck down more total power (~10MW, up from Titan's ~9MW).
These two supercomputers are worth $325 million USD (combined). They are expected to go online in 2017. According to Reuters, an additional $100 million USD will go toward research into "extreme" supercomputing.