gpu sharing

MIG carves an H100 into up to seven hardware slices with their own SMs, memory and bandwidth; MPS lets processes share one SM pool through a single context. One gives fault and performance isolation at a fixed slice size; the other gives flexibility and a shared failure domain. The numbers that decide it.

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.