edit: 32GB is confirmed here https://www.nvidia.com/en-us/geforce/graphics-cards/50-serie...

Supposedly, this image of a Inno3D 5090 box leaked, revealing 32GB of VRAM. It seems like the 5090 will be more of a true halo product, given the pricing of the other cards.

https://www.techpowerup.com/330538/first-nvidia-geforce-rtx-...