S-LoRA is an optimization technique for running thousands of separate large language models (LLMs) simultaneously on a single GPU, addressing the cold-start problem that occurs when infrequently-used models are loaded. This approach leverages fine-tuning methods like LoRA to reduce the required memory and computational resources, enabling efficient serving of multiple task-specific fine-tuned models. By utilizing a tiered caching architecture and custom CUDA kernels, S-LoRA can load many adapters from the same base model onto one GPU, improving throughput and reducing response times, making it possible to deploy many small specialist models efficiently.