Enterprise grade workstations and servers can be configured with 1TB of ram though, so it's not completely inconceivable that you could have a dedicated GPU workstation with 1TB of graphics ram. I mean the Tesla A100 cards have 40GB of VRam each so you'd only need 26 of them to have 1TB of VRAM in a single machine. While I have no idea if such a machine exists, it certainly could exist, 26 GPUs wouldn't fill even half of a server cabinet.
Edit: actually Quattro A6000 cards ship with 48GB vram each, so you only need 22 of those to have 1TB total.
Edit: actually Quattro A6000 cards ship with 48GB vram each, so you only need 22 of those to have 1TB total.