While memory is doubled to 48 GB ... NVIDIA RTX TITAN ADA prototype had a fully enabled AD-102 GPU and while having twice as much memory as the current flagship GPU, it was using slower VRAM ...
TL;DR: NVIDIA's GeForce RTX 4090, originally with 24GB of GDDR6X memory, has been modded in China to feature 48GB of VRAM, selling for $3400. NVIDIA's previous-gen GeForce RTX 4090 graphics card ...