How to Fix "CUDA Out of Memory" Errors on GPU Servers A CUDA out of memory error means your GPU's VRAM is completely full. This memory is consumed by your model weights, activations, gradients, and optimizer states (Adam optimizers take up a massive amount of memory). Before you assume you need a larger GPU, try these code-level fixes: Check for Zombie Processes: Run nvidia-smi in your terminal. If a previous script crashed, it might still be holding VRAM. Kill it with kill -9 <PID> . Reduce Batch Size: This is the easiest fix. Cut your batch size in half. To keep your training stable, implement gradient accumulation so the model updates as if it had a larger batch. Automatic Mixed Precision (AMP): Use PyTorch's autocast . This shifts parts of your model to FP16 or BF16 math, instantly cutting memory usage by nearly 50% without hurting accuracy. Gradient Checkpointing: This trades time for memory. Instead of storing all activations for the backward pass,...