I have run AWS infrastructure for years. When I started looking at how large language models actually get served, I hit a wall on something basic.

Someone said "the model sits on the GPU." Someone else said "the GPU does the calculation." Both sounded right. Neither told me where the model actually lives.

The problem is that "GPU" is not one thing.

Two parts, one board

You already know how a normal machine is laid out. A CPU does the work. RAM holds the data. They sit apart, connected by a bus.