The Volta-based DGX-1 system is over 2 times faster than the Pascal-based systems in compute benchmarks. If the performance gains in games are similar to the compute ones, the GTX 2000 series could be a hit.
https://www.notebookcheck.net/First-compute-performance-test-results-for-Nvidia-s-Volta-Tesla-GPU-revealed.249248.0.html