There is something I think people have missed from a business point of view on this top so thought I would address it here.
I think the tegra X1 in the shield TV is just Nvidia trying to maximise their profit per unit sold. They don't sell many of them comparatively when put against typical consoles so they need to make a lot per unit sold to justify its existence. They also earn much less from software sold unlike a console manufacturer.
With something like the switch the profit per unit can be lower due to much larger projected sales, so whilst the x1 in the shield may be there for cost cutting purposes it doesn't mean the switch will follow suit.
There is also another factor, target audience, target performance.
Android apps do not need a 1 tflop GPU or a super powerful cpu, and a set top box doesn't need to be power efficient. Game stream tech can also be done on limited hardware so there is literally no need for them to put a better chip in the unit. Nvidia isn't going to release a super powerful set top box that can run pc games natively because…. Well see how well steam machines sold to get an idea of that. They know who buys shield TV devices, people who want a premium set top box experience with some added game streaming goodies (premium steam link.)
The switch needs power efficiency and general compute power to run modern games and this is why I believe it will be pascal, pascal is perfect for the efficiency side of things. There is a reason Nintendo ditched Nvidia when it came to the SoC for the 3ds, because tegra was not ready. Nvidia wants to expand into the console market to earn more money and cut into AMD's sales, of course they are going to want to show off what they can do with a limited power envelope so Sony and Microsoft may consider them again. So we will see come Jan 12th!
Discussion started at here by ShaunSwitch