Hello!
I tried to play at 4K Ultra settings. In menu I see near 5000mb VRAM usage.
But I've got max 30 fps, drops to 20 fps, when GPU usage is 99%, CPU is 40%, RAM 6000MB/16000MB.
I've tried smaller settings, and usage in menu is showing 3800mb VRAM usage, but FPS is like the same.
I'm playing at I7 4790K, MSI Geforce GTX 1080, 16 GB RAM.
Witcher 3 is running without problems at 4K Uber settings.
It's game optimization sucks?