Best LLM Models for the NVIDIA RTX 4090
Best consumer GPU for local 7B–34B model inference
The RTX 4090's 24 GB GDDR6X and 1,008 GB/s bandwidth make it the fastest consumer GPU for local LLM inference. It runs Llama 3.1 8B at 100+ tokens/sec in BF16, Llama 3.3 70B in Q4 at 20–30 tokens/sec, and Mistral 7B at near-real-time speeds. For developers running local inference with llama.cpp, Ollama, or LM Studio, the 4090 is the default recommendation. Two 4090s (48 GB combined via llama.cpp split) can run 70B models in Q5 comfortably.
Recommended Models (24GB Ada Lovelace)
Common Use Cases
VRAM Sizing Guide for NVIDIA RTX 4090
BF16 (full precision): requires ~2 bytes per parameter. On 24GB VRAM, the maximum model size in BF16 is approximately 12288B parameters (leaving ~10% headroom for KV cache).
INT8 quantisation: halves memory to ~1 byte/param — fits up to ~24576B parameters. Minimal quality loss on most models.
INT4 / Q4 quantisation: ~0.5 bytes/param — fits up to ~49152B parameters. Recommended for 70B+ models on this GPU. Use GPTQ or AWQ for best quality.
KV cache: grows with context length and batch size. At 128K context with batch size 8, a 70B model in INT4 needs ~12GB additional VRAM for KV cache. Factor this into your serving configuration.