[ИАД, весна 2026] Математические методы анализа текстов. Лекция 7: Training LLMs от 31.03.2026

[ИАД, весна 2026] Математические методы анализа текстов. Лекция 7: Training LLMs от 31.03.2026

🎙 Machine Learning – Intelligent Systems 👥 8K 📅 May 16, 2026 ⏱ 60 min 👁 77 📄 lecture 🧭 2026-08-16
Available in: English (current) Français

Keywords

LLMtrainingmemoryparallelismZeRO

Summary

This lecture, part of a course on mathematical methods for text analysis, focuses on training large language models (LLMs) efficiently. The presenter begins by motivating the need for distributed training, citing examples like LLaMA 3 (405B parameters, 16,000 GPUs) and DeepSeek V3 (2,000 GPUs). The core challenges are memory, compute efficiency, and communication. The lecture then details the memory footprint of training: parameters, gradients, optimizer states, and activations. For a 7B model in FP32, this totals 112 GB for the first three, exceeding the 80 GB of an H100. Mixed precision training (FP16/BF16) is introduced as a standard, but it does not reduce total memory due to master weights; its benefits are faster compute and reduced activation memory. Activation memory is highlighted as the dominant cost, especially with long sequences. Techniques to reduce activation memory are presented: gradient checkpointing (full and selective) and gradient accumulation. The lecture concludes with an introduction to data parallelism and the ZeRO technique (stages 1-3), with FSDP as ZeRO-3, promising to cover more parallelism in the next lecture.

173 words

Critical Evaluation

Value of the Information & Strength of the Argument

The lecture provides a solid overview of the fundamental challenges and techniques in training LLMs. It uses concrete examples (LLaMA 3, DeepSeek V3) and quantitative memory calculations to illustrate the scale of the problem. The argumentation is logical, building from single-GPU limitations to distributed strategies. The explanation of mixed precision and its paradox (no memory savings) is clear. The presentation of gradient checkpointing and accumulation is practical, with trade-offs explained. The introduction to ZeRO is well-structured, showing how it addresses memory bottlenecks. However, the lecture is introductory and does not delve into advanced implementation details or recent research beyond the Hugging Face guide.

Scientific Rigor, Source Quality, Title Accuracy

The lecture is based on the Hugging Face LLM training guide, which is a reputable and practical resource. The presenter mentions this source and recommends it. However, no specific papers or primary sources are cited directly in the video. The content is accurate and aligns with current best practices. The title accurately reflects the content, focusing on training LLMs. The lecture is well-structured and technically sound, though it relies on secondary sources.

190 words

Title / Content Match

The title accurately reflects the content: a lecture on training large language models, covering memory optimization and parallelism techniques.

Quality & Reliability

8/10

The lecture is based on the Hugging Face LLM training guide and covers established techniques (mixed precision, gradient checkpointing, gradient accumulation, ZeRO/FSDP). The presenter explains concepts clearly and provides quantitative examples. However, no primary sources are cited directly in the video, and the content is a summary of existing knowledge.

Key Moments

Cited Sources

  • Hugging Face LLM training guide — The lecturer bases the lecture on this guide, which describes scaling experiments on thousands of GPUs.

Concurring Sources

  • Hugging Face LLM training guide — The lecture directly follows this guide, which is a reputable source for practical LLM training.

Contribution & Novelties

The lecture provides a clear and structured introduction to the key techniques for training large language models, synthesizing information from the Hugging Face guide. It emphasizes the trade-offs between memory, compute, and communication, and explains the paradox of mixed precision. The presentation of gradient checkpointing and accumulation is practical and accessible.

Pour aller plus loin :

115 words

Radar Profile

The radar profile shows high scores across all dimensions, indicating a well-balanced and informative lecture. The technical level is high, and the information is both quantitative and qualitative, with good reliability.

Reliability 8/10