It is now becoming increasingly clear that the purported NVIDIA Ampere GA102 flagship GPU will come in three variants with memory capacities between 10 GB and 24 GB. NVIDIA may launch the flagship GA102-400 variant as an RTX 3090 or a new second gen Titan variant. Also, whether Ampere would actually use GDDR6X VRAM is still anybody's guess at this point.
https://www.notebookcheck.net/NVIDIA-Ampere-GA102-variants-more-or-less-confirmed-RTX-3090-vs-Titan-conundrum-still-remains.476929.0.html