Very unlikely we will see new consoles before 2020 since ms/sony need 7nm transistor technology to provide a substantial GPU leap within the 399-499 USD cost range. The first AMD 7nm graphic cards (VEGA 20 NAVI 10) has a target for fall/spring 2018 (http://www.tweaktown.com/news/55875/amd-launch-monster-navi-10-2019-next-gen-ram/index.html). Add some delays and the fact that consoles usually use a few years old graphic technology (and add the existence of the half gen consoles) and fall 2020 or later seems likely.
Given that the first two 7nm AMD cards planned for 2018 are 20-30 TFLOPS cards, I expect at least 10 TFLOPS for the new consoles (but 15 may be more likely). A GPU twice as capable of scorpio (at least 12 TFLOPS) combined with Ryzen would provide a substantial leap over both XB1X and PS PRO, i think. CPU is a huge bottleneck in the current gen consoles, dont forget that. I bet we will see very few multiplat AA titles in 60 fps on XB1X (destiny, the new ass creed, athem are all 30 fps on XB1X)
Given that the first two 7nm AMD cards planned for 2018 are 20-30 TFLOPS cards, I expect at least 10 TFLOPS for the new consoles (but 15 may be more likely). A GPU twice as capable of scorpio (at least 12 TFLOPS) combined with Ryzen would provide a substantial leap over both XB1X and PS PRO, i think. CPU is a huge bottleneck in the current gen consoles, dont forget that. I bet we will see very few multiplat AA titles in 60 fps on XB1X (destiny, the new ass creed, athem are all 30 fps on XB1X)