A complete guide to building a custom LLM setup with NVIDIA ChatRTX
Published: May 25, 2025
Artificial Intelligence has transformed from a distant technology to something we can now run right from our homes. With advances in consumer hardware and open-source language models, you can build your own AI system to answer questions, generate content, and process information — all on your personal computer. This guide focuses on creating a custom Large Language Model (LLM) setup using NVIDIA’s ChatRTX technology, explaining system requirements, compatible hardware, and providing a cost breakdown for building your own AI powerhouse.
Understanding ChatRTX: NVIDIA’s Local LLM Solution
ChatRTX is NVIDIA’s answer to running powerful language models locally on your PC. Instead of relying on cloud-based systems like ChatGPT, ChatRTX allows you to create a custom chatbot that runs entirely on your own hardware, providing both privacy and performance.
What Makes ChatRTX Special?
ChatRTX isn’t just another AI program — it’s a comprehensive environment for personalized AI interactions. Here’s what it offers:
- Personalized AI: Connect language models to your own content (documents, notes, images)
- Fully Local Processing: Everything runs on your PC, ensuring privacy and security
- Multiple File Format Support: Works with TXT, PDF, DOC/DOCX, JPG, PNG, GIF, and XML files
- Voice Integration: Talk to ChatRTX with built-in speech recognition
- Retrieval-Augmented Generation (RAG): Gets contextually relevant answers from your content
Unlike cloud-based AI services that send your data to remote servers, ChatRTX leverages the power of your NVIDIA RTX GPU to run sophisticated language models right on your desktop.
System Requirements: What You’ll Need
Before diving into the installation process, it’s important to make sure your system meets the requirements for running ChatRTX effectively.
Minimum Hardware Requirements
Component | Requirement | Notes |
---|---|---|
GPU | NVIDIA GeForce RTX 30 or 40 Series with 8GB+ VRAM Or NVIDIA GeForce RTX 5090/5080 |
RTX 3090, 4080, or 4090 recommended for best performance |
RAM | 16GB+ | 32GB or more recommended for smoother operation |
Operating System | Windows 11 | Latest updates recommended |
Storage | 70GB+ free space | SSD strongly recommended for faster model loading |
CPU | Modern multi-core processor | Intel Core i5/i7/i9 or AMD Ryzen 5/7/9 |
GPU Drivers | Version 572.16 or higher | Always use the latest NVIDIA drivers |
Compatible GPUs: Choosing the Right Hardware for LLMs
Your GPU is the most crucial component for running LLMs locally. Let’s break down the options by performance tier:
High-End Consumer GPUs
NVIDIA RTX 4090
The RTX 4090 is currently the king of consumer GPUs for running LLMs locally:
- VRAM: 24GB GDDR6X
- Performance: Excellent for running medium to large models (up to 30B parameters with quantization)
- Power Consumption: 450W active, ~100W idle
- Cost: ~$1,500
- Best For: Serious AI enthusiasts who want to run larger models locally
NVIDIA RTX 4080
A strong alternative with slightly less VRAM:
- VRAM: 16GB GDDR6X
- Performance: Great for small to medium models (up to 13B parameters)
- Power Consumption: ~320W active, ~80W idle
- Cost: ~$1,000
- Best For: Users who want to run models like Phi-3 Mini, Mistral 7B, or Llama 3 8B
NVIDIA RTX 3090
Last generation’s flagship still offers excellent value for LLMs:
- VRAM: 24GB GDDR6X
- Performance: Similar to RTX 4080 but with more VRAM
- Power Consumption: 350W active, ~100W idle
- Cost: ~$780 (used)
- Best For: Budget-conscious users who still want 24GB VRAM
LLM Models: What Can Run on Your Hardware
Not all language models are created equal, and their size (measured in parameters) significantly impacts what hardware you’ll need to run them.
Small Models (3-8B parameters)
Model | Parameters | Min VRAM | Performance | Suitable GPU |
---|---|---|---|---|
Llama 3 8B | 8 billion | 16GB | Good for general text generation | RTX 3080, 3090, 4080, 4090 |
Mistral 7B | 7 billion | 16GB | Excellent performance-to-size ratio | RTX 3080, 3090, 4080, 4090 |
Phi-3 Mini | 3.8 billion | 8GB | Surprisingly capable for size | RTX 3070, 3080, 4070, 4080, 4090 |
Medium Models (10-30B parameters)
Model | Parameters | Min VRAM | Performance | Suitable GPU |
---|---|---|---|---|
Mixtral 8x7B | 47B (MoE) | 32GB* | Strong general-purpose model | RTX 3090/4090 with quantization |
* With quantization, can run on 24GB VRAM GPUs
Large Models (50B+ parameters)
Model | Parameters | Min VRAM | Performance | Suitable GPU |
---|---|---|---|---|
Llama 3 70B | 70 billion | 40GB* | Near GPT-4 level performance | RTX 3090/4090 with heavy quantization |
* With 4-bit quantization, can potentially run on 24GB VRAM GPUs
Building Your Custom LLM Setup: Cost Breakdown
Let’s examine the costs of building different tiers of LLM-capable PCs:
Entry-Level Setup ($1,500-$2,000)
- GPU: RTX 4080 – $1,000
- CPU: Intel Core i5/i7 or AMD Ryzen 5/7 – $300
- RAM: 32GB DDR5 – $150
- Storage: 1TB NVMe SSD – $100
- Other: Motherboard, PSU, Case – $350
- Annual Electricity Cost: ~$390 (12h/day usage)
Capable of running: Small models (Phi-3 Mini, Mistral 7B, Llama 3 8B)
Mid-Range Setup ($2,500-$3,500)
- GPU: RTX 4090 – $1,500
- CPU: Intel Core i9 or AMD Ryzen 9 – $500
- RAM: 64GB DDR5 – $250
- Storage: 2TB NVMe SSD – $200
- Other: Motherboard, PSU, Case – $550
- Annual Electricity Cost: ~$470 (12h/day usage)
Capable of running: Small to large models with optimization (up to Llama 3 70B with quantization)
Budget Alternative ($1,300-$1,800)
- GPU: Used RTX 3090 – $780
- CPU: Intel Core i5/i7 or AMD Ryzen 5/7 – $300
- RAM: 32GB DDR4 – $100
- Storage: 1TB NVMe SSD – $100
- Other: Motherboard, PSU, Case – $300
- Annual Electricity Cost: ~$470 (12h/day usage)
Capable of running: Same as the mid-range setup but at a slower speed and lower cost
Cost-Benefit Analysis: Local Hardware vs. API Services
One important consideration is whether building a local setup is more cost-effective than using cloud-based API services:
- Local Hardware First-Year Cost: $1,250 (RTX 3090 + electricity)
- Token Generation Rate: ~20 tokens/second
- Annual Token Generation: ~315M tokens (12h/day usage)
- Equivalent API Cost: ~$202 (using DeepInfra/Groq at $0.64 per 1M tokens)
- Break-even Point: Over 6 years for average usage
Installing and Setting Up ChatRTX
Once you have compatible hardware, installing ChatRTX is relatively straightforward:
Step 1: Prepare Your System
- Update Windows to the latest version
- Install the latest NVIDIA drivers (572.16 or higher)
- Ensure you have at least 70GB of free disk space
Step 2: Download ChatRTX
- Visit the NVIDIA ChatRTX download page
- Click “Download Now” and save the installer
Step 3: Installation
- Run the ChatRTX installer (e.g., ChatRTX_0.5.exe)
- The installer will verify your system compatibility
- Choose installation directory (default or custom)
- Complete the installation process
Step 4: First Launch and Configuration
- Launch ChatRTX from the Start menu
- Select your preferred language model
- Point the application to folders containing your personal documents
- Wait for initial indexing to complete
Step 5: Start Using Your Custom LLM
- Ask questions related to your personal documents
- Use voice commands by clicking the microphone icon
- Search through your indexed content, including images
Advanced Optimization Techniques
To get the most out of your local LLM setup, especially when running larger models, consider these optimization techniques:
Model Quantization
Quantization reduces the precision of the model’s weights, significantly decreasing memory requirements with minimal performance loss:
- 8-bit Quantization: Reduces VRAM requirements by roughly 50%
- 4-bit Quantization: Reduces VRAM requirements by roughly 75%
- Recommended Tools: GPTQ, bitsandbytes, LLM.int8()
Efficient Inference with vLLM
vLLM is an open-source library that accelerates LLM inference through optimized memory management:
- Uses PagedAttention algorithm to manage attention keys and values
- Allows running models larger than your GPU’s VRAM capacity
- Significantly improves inference speed
Multi-GPU Strategies
If you have multiple GPUs, you can distribute model computation:
- Tensor Parallelism: Splits individual operations across GPUs
- Pipeline Parallelism: Assigns different layers to different GPUs
Alternatives to Consider
While ChatRTX offers a solid experience, there are other approaches to running LLMs locally:
Other Local LLM Interfaces
- LM Studio: User-friendly interface for running various open-source LLMs
- Ollama: Simple command-line tool for running LLMs locally
- Text Generation WebUI: Comprehensive web interface with extensive options
- GPT4All: Local AI assistant with optimized models for consumer hardware
Cloud GPU Rentals
For occasional heavy workloads, consider renting cloud GPUs:
- RunPod: Offers on-demand GPU rentals at competitive prices
- Vast.ai: Marketplace for renting GPUs from individuals and businesses
- Lambda Labs: Professional GPU cloud with optimized ML environments
API-Based Alternatives
- OpenAI API: Access to GPT models with $0.50-$15 per 1M tokens
- Anthropic Claude API: High-quality alternative to GPT
- Groq: Extremely fast inference for open-source models
- DeepInfra: Low-cost API access to various open models
Conclusion: Is Building a Local LLM Setup Right for You?
Building a custom LLM setup with technologies like NVIDIA ChatRTX opens up powerful AI capabilities right on your desktop. Whether this approach is right for you depends on your specific needs and priorities:
Consider a Local LLM Setup If:
- You value data privacy and security above all
- You need offline access to AI capabilities
- You want to customize and fine-tune models
- You’re an AI enthusiast interested in the technical aspects
- You have consistent, high-volume usage that would make API costs prohibitive long-term
Consider API Services If:
- You’re looking for the most cost-effective solution for occasional use
- You need access to the very latest and largest models
- You want to avoid technical complexities
- You require the highest possible performance
- You have limited upfront budget for hardware
The good news is that the barrier to entry for running powerful AI locally continues to decrease. As hardware improves and models become more efficient, the experience will only get better. Whether you choose to build a custom setup now or wait for the next generation of hardware, the ability to harness AI capabilities locally represents an exciting development in computing that puts unprecedented power in the hands of individuals.