Gpu Ai Infrastructure Basics
PART 12 — GPU / AI Infrastructure Basics¶
Models are getting too big for one GPU (an H100 has 80GB VRAM; a 70B model needs ~140GB).
Distributed Inference:
1. Tensor Parallelism (TP): We slice the matrix math itself. GPU 1 computes W_left * x, GPU 2 computes W_right * x, and they sum the result.
* SDE Analogy: Intra-request parallelism. Requires incredibly fast networking (NVLink) because they sync every millisecond. GPUs must be in the same physical server.
2. Pipeline Parallelism (PP): GPU 1 holds layers 1-40. GPU 2 holds layers 41-80.
* SDE Analogy: Microservices. Request goes to Node A, then Node A passes it to Node B. Higher latency, but allows scaling across different physical servers via ethernet.