Playstation 5 & Xbox Two are going to be Monsters!

[Pemalite]

DonFerrari said:

Well can you please explain why or by how much in 2020 we couldn't have a PS4-like portable?

In 2020 it could be possible.
But it's not currently possible with today's technology, we can get "close enough" though.

The biggest issue is going to be memory bandwidth... Mobile devices typically need to use low-voltage DDR, LPDDR4 isn't scaling high enough in clockrates to be a viable alternative to the GDDR5 in the Playstation 4 just yet.

AMD and nVidia are slowly making use/getting around limited bandwidth via technologies like Delta Colour Compression and Tiled Rasterization with better culling... But there is still 100GB/s or more of bandwidth to make up for.

Things might change once LPDDR5 becomes common place.