It shows up as "Shared GPU memory" in Task Manager. What BIOS sets is the Dedicated i.e. reserved video memory in RAM. e.g. My Ryzen iGPU reserves 2GB/32GB for

It shows up as "Shared GPU memory" in Task Manager. What BIOS sets is the Dedicated i.e. reserved video memory in RAM. e.g. My Ryzen iGPU reserves 2GB/32GB for itself (which Windows can't see) via BIOS and use 9 more as shared "unified" memory.