Large model inference optimization involves multiple interrelated technical dimensions. Key areas that LLM Inference Lab may cover include:
Quantization: Compressing model weights from FP16 or FP32 to INT8, INT4, or even lower precision, significantly reducing memory usage and computation while maintaining acceptable accuracy. This includes two main approaches: Post-Training Quantization (PTQ) and Quantization-Aware Training (QAT), as well as specific algorithm implementations like GPTQ, AWQ, and GGUF.
KV Cache Optimization: The autoregressive generation feature of the Transformer architecture makes KV cache management a key to inference efficiency. Important optimization directions include designing efficient cache strategies, handling cache bloat under long contexts, and implementing PagedAttention.
Batching and Scheduling: Maximizing GPU utilization and balancing latency and throughput through continuous batching and request scheduling strategies. This involves complex queuing theory, priority management, and resource allocation algorithms.
Model Parallelism and Distributed Inference: When a single GPU cannot accommodate the entire model, computation needs to be distributed across multiple devices via tensor parallelism, pipeline parallelism, or expert parallelism. The selection and configuration of these parallel strategies directly affect system performance.
Speculative Decoding: Using a small model to quickly generate candidate tokens, then verifying them with a large model, leveraging GPU parallelism to accelerate overall generation speed. This is an important breakthrough in the field of inference acceleration in recent times.