Quantization

Introduction Large language models (LLMs) have transformed natural‑language processing (NLP) across research and industry. Yet the majority of breakthroughs still rely on cloud‑based GPUs or specialized accelerators. For many applications—smartphones, wearables, industrial sensors, and autonomous drones—sending data to the cloud is impractical due to latency, privacy, or connectivity constraints. Edge inference solves this problem by running models locally, but it also imposes strict limits on memory, compute, and power consumption. ...

Table of Contents Introduction Why Quantize? The Gap Between 100B Models and Consumer Hardware Fundamentals of LLM Quantization 3.1 Post‑Training Quantization (PTQ) 3.2 Quant‑Aware Training (QAT) 3.3 Common Bit‑Widths and Their Trade‑offs State‑of‑the‑Art Quantization Techniques for 100B‑Scale Models 4.1 GPTQ (Gradient‑Free PTQ) 4.2 AWQ (Activation‑Aware Weight Quantization) 4.3 SmoothQuant 4.4 BitsAndBytes (bnb) 4‑bit & 8‑bit Optimizers 4.5 Llama.cpp & GGML Backend Hardware Landscape for Edge Inference 5.1 CPU‑Centric Platforms (AVX2/AVX‑512, ARM NEON) 5.2 Consumer GPUs (NVIDIA RTX 30‑Series, AMD Radeon) 5.3 Mobile NPUs (Apple M‑Series, Qualcomm Snapdragon) Practical Walk‑Through: Quantizing a 100B Model for a Laptop GPU 6.1 Preparing the Environment 6.2 Running GPTQ with BitsAndBytes 6.3 Deploying with Llama.cpp 6.4 Benchmarking Results Edge‑Case Example: Running a 100B Model on a Raspberry Pi 5 Best Practices & Common Pitfalls Future Directions: Sparse + Quantized Inference, LoRA‑Fusion, and Beyond Conclusion Resources Introduction Large language models (LLMs) have exploded in size, with the most capable systems now exceeding 100 billion parameters. While these models deliver impressive reasoning, code generation, and multimodal capabilities, their raw memory footprint—often hundreds of gigabytes—places them firmly out of reach for anyone without a data‑center GPU cluster. ...

Table of Contents Introduction Background: Vector Search & Retrieval‑Augmented Generation (RAG) Challenges of Large‑Scale Production Deployments Fundamentals of Quantization 4.1 Scalar vs. Vector Quantization 4.2 Product Quantization (PQ) and Variants Quantization Techniques for Vector Search 5.1 Uniform (Scalar) Quantization 5.2 Product Quantization (PQ) 5.3 Optimized Product Quantization (OPQ) 5.4 Additive Quantization (AQ) 5.5 Binary & Hamming‑Based Quantization Integrating Quantization into RAG Pipelines 6.1 Index Construction 6.2 Query Processing Performance Metrics and Trade‑offs Practical Implementation Walk‑throughs 8.1 FAISS Example: Training & Using PQ 8.2 ScaNN Example: End‑to‑End Pipeline Hyper‑parameter Tuning Strategies Real‑World Case Studies Best Practices & Common Pitfalls 12Future Directions Conclusion Resources Introduction Retrieval‑Augmented Generation (RAG) has become the de‑facto paradigm for building LLM‑powered applications that need up‑to‑date, factual knowledge. At the heart of any RAG system lies a vector search engine that can quickly locate the most relevant passages, documents, or multimodal embeddings from a corpus that can easily stretch into billions of items. ...

Introduction Edge intelligence—running artificial‑intelligence (AI) workloads directly on devices such as wearables, drones, industrial sensors, and IoT gateways—has moved from a research curiosity to a commercial necessity. The promise is clear: lower latency, enhanced privacy, and reduced bandwidth costs because data never has to travel to a remote cloud. However, edge devices are constrained by limited compute, memory, and energy budgets. Two complementary techniques have emerged as the most effective ways to bridge the gap between the computational demand of modern deep‑learning models and the modest resources of edge hardware: ...

Introduction Artificial intelligence has long been dominated by cloud‑centric architectures. Massive language models such as GPT‑4, Claude, and LLaMA are trained on clusters of GPUs, stored in data‑center warehouses, and accessed via APIs that route every request through the internet. While this model‑as‑a‑service approach delivers impressive capabilities, it also introduces latency, recurring costs, vendor lock‑in, and, most critically, privacy concerns. The local‑first AI movement seeks to reverse this trend by moving inference—and, increasingly, fine‑tuning—onto the very devices that generate the data: smartphones, laptops, single‑board computers, and other consumer‑grade edge hardware. The catalyst for this shift is quantization, a set of techniques that compress the numerical precision of model weights from 16‑ or 32‑bit floating point to 8‑bit, 4‑bit, or even binary representations. Quantized models occupy a fraction of the memory footprint of their full‑precision counterparts and can run on CPUs, low‑power GPUs, or specialized AI accelerators. ...