Network Optimization

Introduction Training modern deep‑learning models—think GPT‑4‑scale transformers, ResNet‑152, or large recommendation systems—requires massive computational resources. A single GPU can no longer finish a training epoch in a reasonable amount of time, so practitioners turn to distributed training across dozens or even hundreds of accelerators. While the high‑level idea—split work, sync gradients, repeat—sounds simple, achieving linear scaling is surprisingly hard. Two low‑level pillars dominate performance: CUDA kernels that run on each GPU. Their efficiency determines how fast a single device can process its share of data. Network communication that stitches the devices together. Latency, bandwidth, and protocol overhead dictate how quickly gradients and parameters are exchanged. In this guide we dive deep into both aspects, exploring theory, practical tuning techniques, and real‑world examples. By the end you’ll have a checklist you can apply to any PyTorch/TensorFlow job, and a concrete case study that demonstrates measurable speed‑ups. ...