Show me footage of RDR2 maxed out at 4K in the Annesburg part of the map never dipping under 60 FPS and I’ll believe you.
Other examples where a single 3090 is not going to cut it.
SOTTR
Metro Exodus
Tarkov
GTA V
I dont know about that part of the map or whether any review has done that bit but I know 3090fe average 75-77 fps on 4k ultra and an overclocked strix 3090 at 480W is 18% faster than a 3090FE so that should pull 90 fps ish.
But i think you will struggle avoiding any dip below 60fps as for some off reason RDR2 seems to have a big problem with its minimum framerates and dips.
The faster the card you use, the lower the minimum becomes.
the 2080 super has a minimum of 34.38 fps but only an average of 44.65 and as you use faster and faster cards this minium drops until eventually using a 3090 you get 31.8 but your average is 75.84 fps
Buggy game?
https://hothardware.com/reviews/nvidia-geforce-rtx-3090-bfgpu-review?page=4