ASUS has just kinda confirmed the GeForce RTX 3080 Ti graphics card, which will reportedly pack a larger 20GB of VRAM over the RTX 3080 and its 10GB -- and 4GB less than the 24GB on the RTX 3090.

The new GeForce RTX 3080 Ti with 20GB of VRAM was spotted on the ASUS website and its support and services page, which lists the ROG STRIX variants of not only the GeForce RTX 3080 Ti with 20GB of VRAM -- but the RTX 3060 with 12GB of VRAM.
ASUS will have overclocked and non-overclocked models of both the GeForce RTX 3080 Ti and GeForce RTX 3060, with their new VRAM amounts to better compete against AMD using 16GB of VRAM across all three of their Big Navi graphics cards in the RX 6800, RX 6800 XT, and RX 6900 XT.
We should expect the 20GB of VRAM on the GeForce RTX 3080 Ti to be at 19Gbps -- slower than the 19.5Gbps used on the RTX 3090, and the same 19Gbps as the RTX 3080. We should see a higher 320-bit memory bus for the VRAM, while the GPU will pack 10496 CUDA cores. This CUDA core count on the GeForce RTX 3080 Ti would give it the same CUDA core count as the GeForce RTX 3090, and way more than the RTX 3080 which packs just 8704 CUDA cores in comparison.