Sizing your hardware
Q: What are the most important hardware factors for running LLMs locally?
A:
Your GPU's VRAM and AI computing capabilities are the most important factors for local AI performance,
followed by system RAM and a modern CPU. Sufficient VRAM determines the maximum model size you can run
efficiently on your PC.
Q: How much VRAM is required for different sizes of AI models?
A:
Weights take about 2 bytes per parameter at FP16, 1 byte at INT8 and 0.5–0.6 bytes at INT4. So a 7B–8B model needs about 8GB at INT8; a 13B about 13GB at INT8 or 7–8GB at INT4; a 30B about 15–18GB at INT4 or 30GB at INT8; a 70B about 35–42GB at INT4 — more than one 32GB card holds. Add about 20% for KV cache and runtime overhead. These are inference figures; training needs substantially more.
Q: What do INT4, INT8 and FP16 mean, and which should I use?
A:
Quantization formats — the bytes used per model parameter. FP16 is about 2 bytes, INT8 about 1, and INT4 about 0.5–0.6 (for example Q4_K_M in the GGUF format). Lower precision fits a larger model into less VRAM, at some cost in quality. A 13B-class model needs about 26GB at FP16, 13GB at INT8 and 7–8GB at INT4. Use INT8 when it fits, INT4 when it does not.
Q: What are the minimum PC specifications needed for running LLMs locally?
A:
8GB of VRAM, 32GB of system RAM and a modern 6-core CPU. VRAM sets the ceiling on model size: 8GB runs 7B–8B-class models at INT4, 12GB runs them at INT8, 16GB runs 13B-class at INT8, and 32GB runs 30B-class at INT4. System RAM only matters once a model exceeds VRAM and layers offload to the CPU, which cuts throughput.
Choosing a GPU
Q: Which GPUs are best for running complex local AI models (like LLaMA, GPT, Mistral, etc.) and handling advanced AI workloads?
A:
The GeForce RTX 5090 is the strongest option in the RTX 50 Series for local AI: its 32GB of VRAM runs 30B-class models at INT4, or 13B-class models at FP16, entirely on-GPU. The 16GB RTX 5080 and RTX 5070 Ti run 13B-class models at INT8; the 12GB RTX 5070 runs 7B–8B-class models at INT8. VRAM sets the ceiling on model size.
Q: Is it better to use multiple lower-end GPUs or a single high-end GPU?
A:
Use one card if the model fits. Multi-GPU only matters when it does not: two 32GB GeForce RTX 5090 cards pool 64GB, enough for a 70B-class model at INT4 (about 35–42GB of weights). Two limits — GeForce RTX 50 Series has no NVLink, so cards communicate over PCIe, and the framework must split model layers across devices (llama.cpp, vLLM and Hugging Face Accelerate do; most applications do not).
Q: Is NVIDIA or Radeon better for running AI workloads?
A:
It depends mainly on your software. Most local AI tooling — llama.cpp, Ollama, LM Studio, vLLM and PyTorch — ships CUDA as its default path, so NVIDIA GPUs usually run models with no extra setup, while Radeon depends on ROCm, which covers fewer frameworks and operating systems. VRAM also sets the ceiling on model size, and the GeForce RTX 5090's 32GB is the most of any GeForce card. For most local AI builds today, GeForce RTX tends to be the more straightforward starting point.
Q: How do GeForce RTX GPUs compare to Apple's M-series chips for local AI processing tasks?
A:
Different trade-offs. Apple's unified memory lets a high-configuration Mac allocate more memory to a model than any single consumer GPU. GeForce RTX leads on bandwidth and software: the RTX 5090 delivers 1,792 GB/sec, which governs token generation speed, and CUDA is the default target for nearly every AI framework. Choose Apple for the largest models at low power; choose GeForce RTX for the fastest tokens per second.
Software and setup
Q: What software do I need to run a local LLM on a GeForce RTX GPU?
A:
Ollama (simplest, command line), LM Studio (graphical, with a built-in model browser) or llama.cpp (most control) — all free, all run GGUF models, and all use CUDA on GeForce RTX GPUs with no extra configuration. Use vLLM to serve a model to multiple users or applications. You do not need to install CUDA separately; the display driver is enough.
How it works
Q: How do Tensor Cores improve AI performance on GeForce RTX GPUs?
A:
Tensor Cores are dedicated matrix multiply-accumulate units — the operation AI workloads spend most of their time on, and one that general-purpose CUDA cores handle far less efficiently. On GeForce RTX 50 Series GPUs, 5th generation Tensor Cores add FP4 alongside FP8 and FP16, delivering from 988 AI TOPS on the RTX 5070 to 3,352 AI TOPS on the RTX 5090.
Q: How important is the CPU compared to GPU for AI performance?
A:
The GPU is far more relevant for inference speed and AI processing in games, creative apps, etc. The CPU only comes into play if you're running models larger than your VRAM or using CPU-specific features in some apps.
Q: How stressful is running AI workloads or hosting local AI on my hardware and will it damage components?
A:
Running LLMs is similar in stress to gaming or rendering and won't damage hardware if cooling is adequate. Occasional heavy loads are perfectly safe for modern components as long as the cooling solution can handle heat effectively.
Q: What performance boost does DLSS 4.5 provide on GeForce RTX 50 Series GPUs?
A:
DLSS 4.5 adds two GeForce RTX 50 Series exclusives: 6X Multi Frame Generation, which generates up to five additional frames per traditionally rendered frame, and Dynamic Multi Frame Generation, which adjusts the multiplier to the workload. Its 2nd generation transformer model for Super Resolution runs on all GeForce RTX GPUs. Actual frame rates depend on the GPU, game and resolution.