time slicing

Hardware partitions, shared SMs, and context switching are three different promises about isolation and waste. The slice arithmetic for an H100, what each mode gives up, and the one rule about tenants that decides most of it.

A notebook holds a GPU for eight hours and uses it for twenty minutes, which is what sharing is for and what makes it hard. The sharing mode to pick and the one to refuse across users, the idle-reclaim loop that keeps sessions alive without holding hardware, the quota arithmetic, and how many GPUs 300 users need.