Llama 3.1 8B Instruct is a robust language model developed by Meta, designed to excel in a variety of text generation tasks. With 8 billion parameters, this model offers a balance between performance and resource requirements, making it suitable for generating coherent and contextually relevant text across a wide range of applications, from chatbots and content creation to summarization and translation. The model's context length of 131,072 tokens allows it to handle long-form text, which is particularly useful for tasks requiring deep contextual understanding.
In its size class, Llama 3.1 8B Instruct holds its own, often outperforming models with similar parameter counts in terms of both quality and efficiency. It punches above its weight in generating nuanced and detailed responses, while maintaining a relatively low memory footprint compared to larger models. This makes it an attractive choice for users who need high-quality text generation without the need for extensive computational resources. The available quantizations, including Q4_K_M, Q5_K_M, Q8_0, and FP16, further enhance its efficiency, allowing it to run smoothly on a variety of hardware setups, from mid-range GPUs with 5.1 GB VRAM to more powerful systems with up to 17.0 GB VRAM. Ideal users include developers, researchers, and businesses looking for a versatile and efficient text generation solution that can be deployed on a range of hardware, from personal computers to cloud servers.
| Quantization | Bits | File Size | VRAM Needed | RAM Needed | Quality |
|---|---|---|---|---|---|
| Q4_K_M | 4.5 | 4.583 GB | 5.08 GB | 5.58 GB | 85% |
| Q5_K_M | 5.5 | 5.339 GB | 5.84 GB | 6.34 GB | 90% |
| Q8_0 | 8 | 7.954 GB | 8.45 GB | 8.95 GB | 98% |
| FP16 | 16 | 16 GB | 17 GB | 20 GB | 100% |
Context window & KV cache
Adds 1.00 GB to VRAMLong chats and RAG inputs cost real memory. Drag to see how 32K vs 128K context shifts your grade.
Model native max: 128K tokens. KV-cache estimate is approximate (±30 %); real usage depends on attention layout.
How to run Llama 3.1 8B Instruct
Pick a runtime — copy & paste. Commands are pre-filled with this model’s repo.
Easiest. Single command. OpenAI-compatible API on :11434.
Ollama home →- 1
Pull the model
ollama pull llama3.1:8b - 2
Chat
ollama run llama3.1:8b - 3
Use as API
curl http://localhost:11434/api/chat \ -d '{"model":"llama3.1:8b","messages":[{"role":"user","content":"Hi"}]}'
Community benchmarks
Real tokens/sec reports from people running Llama 3.1 8B Instruct on actual hardware.
| GPU | Median tok/s | Reports | Typical setup |
|---|---|---|---|
| H100 SXM | 245.0 | 1 | Q4_K_M · vLLM · Linux · 8K ctx |
| A100 80GB | 165.0 | 1 | Q4_K_M · vLLM · Linux · 8K ctx |
| RTX 4090 | 95.5 | 2 | Q4_K_M · llama.cpp · Linux · 4K ctx |
| RTX 3090 | 71.8 | 1 | Q4_K_M · Ollama · Linux · 4K ctx |
| RTX 4060 Ti | 51.4 | 1 | Q4_K_M · Ollama · Windows · 4K ctx |
| M3 Max | 47.5 | 1 | Q4_K_M · MLX · macOS · 4K ctx |
| M2 Pro | 27.1 | 1 | Q4_K_M · Ollama · macOS · 4K ctx |
Self-host serving plan
Want to host Llama 3.1 8B Instructfor many users? Or run it on a card that’s technically too small? Slide the knobs.
VRAM needed
6.3 GB
5.1 GB weights + 0.7 GB KV
Aggregate tok/s
31
across 1 user
Per-user tok/s
31
8 B dense
✅ Fits in 24 GB VRAM with 17.7 GB headroom. Pure-GPU inference — full speed.
Throughput is a sub-linear estimate: doubling users adds ~70 % of single-user TPS until ~8, then plateaus on memory bandwidth. MoE models scale concurrency much better because each user activates a different subset of experts.
See It In Action
Real model outputs generated via RunThisModel.com — watch responses stream in real time.
Outputs generated by real AI models via RunThisModel.com. Generation speed shown is from cloud inference. Local speeds vary by hardware — check your device.
how much VRAM do I need to run Llama 3.1 8B Instruct?
Llama 3.1 8B Instruct requires 5.08 GB VRAM minimum with Q4_K_M quantization. For full precision you need 17 GB.
which quant should I pick?
Q4_K_M is the best quality/VRAM balance — ~92% of FP16 quality at ~25% the footprint. Q8_0 is near-lossless if you have the headroom.