Efficient Large Language Models: A Survey

Efficient Large Language Models: A Survey [arXiv] (Version 1: 12/06/2023; Version 2: 12/23/2023; Version 3: 01/31/2024; Version 4: 05/23/2024, camera ready version of Transactions on Machine Learning Research)

Zhongwei Wan¹, Xin Wang¹, Che Liu², Samiul Alam¹, Yu Zheng³, Jiachen Liu⁴, Zhongnan Qu⁵, Shen Yan⁶, Yi Zhu⁷, Quanlu Zhang⁸, Mosharaf Chowdhury⁴, Mi Zhang¹

¹The Ohio State University, ²Imperial College London, ³Michigan State University, ⁴University of Michigan, ⁵Amazon AWS AI, ⁶Google Research, ⁷Boson AI, ⁸Microsoft Research Asia

⚡News: Our survey has been officially accepted by Transactions on Machine Learning Research (TMLR) 2024. Camera ready version is available at: [OpenReview]

@article{wan2023efficient,
  title={Efficient large language models: A survey},
  author={Wan, Zhongwei and Wang, Xin and Liu, Che and Alam, Samiul and Zheng, Yu and others},
  journal={arXiv preprint arXiv:2312.03863},
  volume={1},
  year={2023},
  publisher={no}
}

❤️ Community Support

This repository is maintained by tuidan (wang.15980@osu.edu), SUSTechBruce (wan.512@osu.edu), samiul272 (alam.140@osu.edu), and mi-zhang (mizhang.1@osu.edu). We welcome feedback, suggestions, and contributions that can help improve this survey and repository so as to make them valuable resources to benefit the entire community.

We will actively maintain this repository by incorporating new research as it emerges. If you have any suggestions regarding our taxonomy, find any missed papers, or update any preprint arXiv paper that has been accepted to some venue, feel free to send us an email or submit a pull request using the following markdown format.

Paper Title, <ins>Conference/Journal/Preprint, Year</ins>  [[pdf](link)] [[other resources](link)].

📌 What is This Survey About?

Large Language Models (LLMs) have demonstrated remarkable capabilities in many important tasks and have the potential to make a substantial impact on our society. Such capabilities, however, come with considerable resource demands, highlighting the strong need to develop effective techniques for addressing the efficiency challenges posed by LLMs. In this survey, we provide a systematic and comprehensive review of efficient LLMs research. We organize the literature in a taxonomy consisting of three main categories, covering distinct yet interconnected efficient LLMs topics from model-centric, data-centric, and framework-centric perspective, respectively. We hope our survey and this GitHub repository can serve as valuable resources to help researchers and practitioners gain a systematic understanding of the research developments in efficient LLMs and inspire them to contribute to this important and exciting field.

🤔 Why Efficient LLMs are Needed?

Although LLMs are leading the next wave of AI revolution, the remarkable capabilities of LLMs come at the cost of their substantial resource demands. Figure 1 (left) illustrates the relationship between model performance and model training time in terms of GPU hours for LLaMA series, where the size of each circle is proportional to the number of model parameters. As shown, although larger models are able to achieve better performance, the amounts of GPU hours used for training them grow exponentially as model sizes scale up. In addition to training, inference also contributes quite significantly to the operational cost of LLMs. Figure 2 (right) depicts the relationship between model performance and inference throughput. Similarly, scaling up the model size enables better performance but comes at the cost of lower inference throughput (higher inference latency), presenting challenges for these models in expanding their reach to a broader customer base and diverse applications in a cost-effective way. The high resource demands of LLMs highlight the strong need to develop techniques to enhance the efficiency of LLMs. As shown in Figure 2, compared to LLaMA-1-33B, Mistral-7B, which uses grouped-query attention and sliding window attention to speed up inference, achieves comparable performance and much higher throughput. This superiority highlights the feasibility and significance of designing efficiency techniques for LLMs.

📖 Table of Content

• 🤖 Model-Centric Methods
  • Model Compression
    • Quantization
      • Post-Training Quantization
        • Weight-Only Quantization
        • Weight-Activation Co-Quantization
        • Evaluation of Post-Training Quantization
      • Quantization-Aware Training
    • Parameter Pruning
      • Structured Pruning
      • Unstructured Pruning
    • Low-Rank Approximation
    • Knowledge Distillation
      • White-Box KD
      • Black-Box KD
    • Parameter Sharing
  • Efficient Pre-Training
    • Mixed Precision Training
    • Scaling Models
    • Initialization Techniques
    • Training Optimizers
  • Efficient Fine-Tuning
    • Parameter Efficient Fine-Tuning
      • Adapter-based Tuning
      • Low-Rank Adaptation
      • Prefix Tuning
      • Prompt Tuning
    • Memory Efficient Fine-Tuning
    • MoE Efficient Supervised Fine-Tuning
  • Efficient Inference
    • Parallel Decoding
    • Speculative Decoding
    • KV-Cache Optimization
  • Efficient Architecture
    • Efficient Attention
      • Sharing-based Attention
      • Feature Information Reduction
      • Kernelization or Low-Rank
      • Fixed Pattern Strategies
      • Learnable Pattern Strategies
    • Mixture of Experts
      • MoE-based LLMs
      • Algorithm-Level MoE Optimization
    • Long Context LLMs
      • Extrapolation and Interpolation
      • Recurrent Structure
      • Segmentation and Sliding Window
      • Memory-Retrieval Augmentation
    • Transformer Alternative Architecture
      • State Space Models
      • Other Sequential Models
• 🔢 Data-Centric Methods
  • Data Selection
    • Data Selection for Efficient Pre-Training
    • Data Selection for Efficient Fine-Tuning
  • Prompt Engineering
    • Few-Shot Prompting
      • Demonstration Organization
        • Demonstration Selection
        • Demonstration Ordering
      • Template Formatting
        • Instruction Generation
        • Multi-Step Reasoning
        • Parallel Generation
    • Prompt Compression
    • Prompt Generation
• 🧑‍💻 System-Level Efficiency Optimization and LLM Frameworks
  • System-Level Efficiency Optimization
    • System-Level Pre-Training Efficiency Optimization
    • System-Level Serving Efficiency Optimization
      • Serving System Design
      • Serving Performance Optimization
    • Algorithm-Hardware Co-Design
  • LLM Frameworks

🤖 Model-Centric Methods

Model Compression

Quantization

Post-Training Quantization

Weight-Only Quantization

• I-LLM: Efficient Integer-Only Inference for Fully-Quantized Low-Bit Large Language Models, arXiv, 2024 [Paper]
• IntactKV: Improving Large Language Model Quantization by Keeping Pivot Tokens Intact, arXiv, 2024 [Paper]
• OmniQuant: OmniQuant: Omnidirectionally Calibrated Quantization for Large Language Models, ICLR, 2024 [Paper] [Code]
• OneBit: Towards Extremely Low-bit Large Language Models, arXiv, 2024 [Paper]
• GPTQ: Accurate Quantization for Generative Pre-trained Transformers, ICLR, 2023 [Paper] [Code]
• QuIP: 2-Bit Quantization of Large Language Models With Guarantees, arXiv, 2023 [Paper] [Code]
• AWQ: Activation-aware Weight Quantization for LLM Compression and Acceleration, arXiv, 2023 [Paper] [Code]
• OWQ: Lessons Learned from Activation Outliers for Weight Quantization in Large Language Models, arXiv, 2023 [Paper] [Code]
• SpQR: A Sparse-Quantized Representation for Near-Lossless LLM Weight Compression, arXiv, 2023 [Paper] [Code]
• FineQuant: Unlocking Efficiency with Fine-Grained Weight-Only Quantization for LLMs, NeurIPS-ENLSP, 2023 [Paper]
• LLM.int8(): 8-bit Matrix Multiplication for Transformers at Scale, NeurlPS, 2022 [Paper] [Code]
• Optimal Brain Compression: A Framework for Accurate Post-Training Quantization and Pruning, NeurIPS, 2022 [Paper] [Code]
• QuantEase: Optimization-based Quantization for Language Models, arXiv, 2023 [Paper] [Code]

Weight-Activation Co-Quantization

• OmniQuant: OmniQuant: Omnidirectionally Calibrated Quantization for Large Language Models, ICLR, 2024 [Paper] [Code]
• Intriguing Properties of Quantization at Scale, NeurIPS, 2023 [Paper]
• ZeroQuant-V2: Exploring Post-training Quantization in LLMs from Comprehensive Study to Low Rank Compensation, arXiv, 2023 [Paper] [Code]
• ZeroQuant-FP: A Leap Forward in LLMs Post-Training W4A8 Quantization Using Floating-Point Formats, NeurIPS-ENLSP, 2023 [Paper] [Code]
• OliVe: Accelerating Large Language Models via Hardware-friendly Outlier-Victim Pair Quantization, ISCA, 2023 [Paper] [Code]
• RPTQ: Reorder-based Post-training Quantization for Large Language Models, arXiv, 2023 [Paper] [Code]
• Outlier Suppression+: Accurate Quantization of Large Language Models by Equivalent and Optimal Shifting and Scaling, arXiv, 2023 [Paper] [Code]
• QLLM: Accurate and Efficient Low-Bitwidth Quantization for Large Language Models, arXiv, 2023 [Paper]
• SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models, ICML, 2023 [Paper] [Code]
• ZeroQuant: Efficient and Affordable Post-Training Quantization for Large-Scale Transformers, NeurIPS, 2022 [Paper]

Evaluation of Post-Training Quantization

• Evaluating Quantized Large Language Models, arXiv, 2024 [Paper]

Quantization-Aware Training

• The Era of 1-bit LLMs: All Large Language Models are in 1.58 Bits, arXiv, 2024 [Paper]
• FP8-LM: Training FP8 Large Language Models, arXiv, 2023 [Paper]
• Training and inference of large language