Understanding Large Language Models

Aug 11, 2024

Intro to Large Language Models

Overview

  • Recently gave a 30-minute talk on large language models (LLMs).
  • Re-recording the talk for YouTube due to positive feedback from attendees.

What are Large Language Models?

  • LLMs can be simplified to two files:
    • Parameters File: Contains the weights of the neural network.
    • Run Code File: Contains the code to execute the model, can be in various programming languages (e.g., C, Python).
  • Example: Llama 270B Model by Meta AI.
    • Part of the Llama 2 series with models ranging from 7B to 70B parameters.
    • 70B parameters = 140GB file size (2 bytes per parameter).
  • Allows for running the model on personal devices without internet access.
  • Can generate text based on prompts.

Model Training vs Inference

  • Model Inference: Running the model with available parameters (simple process).
  • Model Training: More complex; involves:
    • Collecting ~10 terabytes of text from the internet (web crawl).
    • Training on a GPU cluster (6,000 GPUs over 12 days).
    • Cost ~ $2 million.
    • Training can be viewed as compressing text data into parameters (like lossy compression).

Neural Network Functionality

  • LLMs primarily predict the next word in a sequence.
  • Example: Given text, predict next most likely word.
  • Relationships exist between prediction and compression.
  • LLMs learn vast information about the world through next-word prediction.

Using Trained Neural Networks

  • Generate outputs by feeding in text and obtaining the next word.
  • Results are often creative outputs (e.g., poetry), but may include inaccuracies or hallucinations.

Transformer Neural Network Architecture

  • Understand the architecture and mathematical operations involved.
  • 100B+ parameters in LLMs are dispersed throughout.
  • Key understanding: We can optimize parameters for better predictions but don't fully understand their functions.

Stages of LLM Development

Stage 1: Pre-Training

  • Involves training on vast internet text (lower quality).
  • Requires significant computational resources.
  • Objective is knowledge accumulation.

Stage 2: Fine-Tuning

  • Shift to high-quality Q&A document training (e.g., human-assisted).
  • Used for creating assistant models that better respond to questions.

Stage 3: Reinforcement Learning from Human Feedback

  • Optional stage to further refine the model based on comparisons of generated responses.
  • Aims to improve output quality through iterative feedback.

Leading Models and Performance

  • Proprietary models (e.g., GPT series) outperform open-source models but lack full accessibility.
  • Ongoing competition between proprietary and open-source models.

Future Directions

Scaling Laws

  • Performance in LLMs is largely predictable based on parameters and training data.
  • Larger models with more data tend to perform better.

Tool Usage

  • LLMs evolve to use tools (e.g., browsing, calculators) to enhance problem-solving abilities.
  • Example of organizing data, performing calculations, or generating visuals through prompts.

Multimodality

  • Ability to process and generate images, audio, and text.
  • Potential for speech-to-speech communication capabilities.

System One vs. System Two Thinking

  • Current LLMs function similarly to instinctive thinking (System One).
  • Future work aims to introduce reflective problem-solving (System Two).

Self-Improvement and Customization

  • Potential for models to improve beyond human imitation.
  • Discussion of methods for tailoring models to specific tasks or functions.

Security Challenges

Types of Attacks

  • Jailbreak Attacks: Bypass safety mechanisms (e.g., roleplay scenarios).
  • Prompt Injection Attacks: Hijack instructions through subtle prompts.
  • Data Poisoning: Introduce harmful operating conditions via training data.

Defense Mechanisms

  • Security measures in place to mitigate various attacks, with ongoing research in this area.

Conclusion

  • LLMs offer a new computing paradigm with vast potential but also face security challenges.
  • Continuous evolution in model capabilities and security measures is critical for future applications.