How do you select GPUs for LLM training and inference, and what specs actually matter?

Picking GPUs is a genuine applied decision, and 'get the biggest one' misses the point. The signal is knowing which spec binds your workload (VRAM, bandwidth, interconnect) and the train-versus-serve difference that flips the answer.

Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.