Question Realtime lighting CPU/GPU and VRAM questions.

Hi!

I'm planning on baking realtime lighting in the near future on a 100km2 open world that I've been working on.
The question is: Does the current realtime lightmapper use the CPU or GPU? And does this change with the upcoming Lightmapper 1.0? I'm working with URP.

I'm going to have to have to buy a new computer and based on the answer I'm going to have to choose between a couple of options:

1. If it uses the GPU, would a Windows PC with a Graphics card with 20+ Gb of VRAM be enough? Because if not then I guess I'll have to buy an Apple Silicon Mac with 128 Gb of Shared Memory. Due to the fact that it can work as both RAM and VRAM.

My World scene contains 16 terrains and I'm not really sure if Unity uses all VRAM for the entire scene of it uses all vram for one terrain and then it flushes all memory and uses it for the next terrain.

2. If it uses the CPU, I guess that I will buy a computer with an AMD CPU and GPU because the CPU can use the GPUs VRAM with AMD Smart Access Memory. And also go for 128 GB of RAM.

(And unfortunately I don't even know if I could bake such a big terrain even going all out with this PC).

I guess I could just not have any baked light data but the visual difference is tremendous.

Thanks for your time!