quick video of what I see in this game all the time now.

https://youtu.be/VQeOvU_Kug4

i recently upgraded from a 3080 to a 4090 along with a 7800x3d and 64gb of ram. DLSS and Frame gen stuff is off. All other settings are maxed out. RT preview on/off doens't matter with this.

entire parts of the world just come and go as I move around. I don't recall this being an issue before my upgrade. I've DDU'd the drivers and reinstalled them.

this doesn't happen in all games and the system is stable otherwise.

From the main menu, go to Settings -> Gameplay.
Make sure "HDD mode" is set to Off.

No change setting it to off.

Was it set to Auto? That setting is apparently a bit finicky, and may require a restart of the game before taking effect.

Also, have you tried disabling RayTracing? Damn sure shouldn't be necessary with a 4090, but it has been known to cause issues with objects not being displayed properly.

yea RT on/off/path tracing on/off etc andd it doesn't change it.