>>401175796
Just so you know, in this conversation one party is someone who has written a rendering engine in vulkan, read all the all nvidia architecture's whitepapers going back to fermi and has personal experience with scaling on different ampere cards.
The other party unironically goes to /g/ to get an "authoritative" opinion.

You just don't understand what you are talking about. 
Alright, let's just make it like this, doom eternal at 4k, 4090 will have at least 1.7x perf of 3090, anything less is just not possible. It is the baseline, I can easily see 1.8x personally.
You can screencap this post. You can also make your own prediction and once reviews drop we will see who was closer to the truth.