AMD's "Biggest Navi" is rumored to be similar to the Radeon VII, featuring HBM2 VRAM and 80 compute units, and Nvidia is apparently planning to counter this with an RTX 3000 Titan GPU equipped with up to 48 GB of 21 Gbps or even 23 Gbps GDDR6x VRAM that may turn out to be only 10% faster than the RTX 3090.
https://www.notebookcheck.net/Nvidia-RTX-3000-Titan-with-48-GB-of-GDDR6x-VRAM-may-launch-to-counter-AMD-s-Biggest-Navi-GPU-in-Q1-2021.493999.0.html