pipeline is really slow - consulting [D]

In three linesUser seeks advice on training bottleneck in robotics imitation learning. Pipeline: 4 RGB cameras 128×128 → frozen ResNet18 → DiT (~50M params, 8 layers) predicting action chunks. A4500 GPU at 20–30% utilization, CPU saturated, ~10 iter/sec. Profiler shows optimizer_step dominant (62.4%).

Summary generated by Claude — human-verified