Llama 3.1 405B: Hardware & Business Fit
- Tools
- Reasoning
- Multilingual
- Long context
Frontier-scale open weights, listed to anchor the high end. Plan for a server cluster or rented cloud GPUs.
- Parameters
- ~405B
- Context
- ~128K tokens
- Deployment
- cloud
- VRAM @ 4-bit
- ~230GB
What Llama 3.1 405B is good for
- ▸Frontier-quality private deployments
- ▸Research-grade reasoning
Best quantization choices
Approximate memory per quantization (weights + KV cache at modest context). Treat as ±.
| Quant | ~Memory | When to use |
|---|---|---|
| Q4_K_M | ~230GB | Best size/quality trade-off — the usual default for local serving. |
| Q8_0 | ~410GB | Higher fidelity; ~1.7× the memory of 4-bit. |
| FP16 | ~810GB | Full precision; largest footprint, best quality. |
Run Llama 3.1 405B locally
Pull and run with Ollama, or grab the weights from Hugging Face.
$ ollama run llama3.1:405bmeta-llama/Llama-3.1-405B-InstructCompatible hardware
Devices from our catalog graded for Llama 3.1 405B, best fit first.
- Supermicro 8x H100 SuperServerSupermicro · AI Servers
Fits at Q8_0 (~410GB) with ~153.2GB headroom — about 1 concurrent instance.
Q8_0 · ~410GBRuns well - Dell PowerEdge XE9680Dell · AI Servers
Fits at Q8_0 (~410GB) with ~153.2GB headroom — about 1 concurrent instance.
Q8_0 · ~410GBRuns well - NVIDIA B200 (placeholder)NVIDIA · Datacenter GPUs
Even the smallest quantization (~230GB) exceeds usable memory (~169GB). Choose a smaller model or step up the hardware.
Not recommended - AMD Instinct MI300XAMD · Datacenter GPUs
Even the smallest quantization (~230GB) exceeds usable memory (~169GB). Choose a smaller model or step up the hardware.
Not recommended - Cloud B200 (Blackwell profile, to verify)Cloud · Cloud GPU Profiles
Even the smallest quantization (~230GB) exceeds usable memory (~158.4GB). Choose a smaller model or step up the hardware.
Not recommended - NVIDIA H200 (141GB)NVIDIA · Datacenter GPUs
Even the smallest quantization (~230GB) exceeds usable memory (~124.1GB). Choose a smaller model or step up the hardware.
Not recommended - Cloud H200 141GB (profile)Cloud · Cloud GPU Profiles
Even the smallest quantization (~230GB) exceeds usable memory (~124.1GB). Choose a smaller model or step up the hardware.
Not recommended - NVIDIA H100 (80GB)NVIDIA · Datacenter GPUs
Even the smallest quantization (~230GB) exceeds usable memory (~70.4GB). Choose a smaller model or step up the hardware.
Not recommended - Cloud H100 80GB (profile)Cloud · Cloud GPU Profiles
Even the smallest quantization (~230GB) exceeds usable memory (~70.4GB). Choose a smaller model or step up the hardware.
Not recommended - NVIDIA RTX PRO 6000 BlackwellNVIDIA · Professional GPUs
Even the smallest quantization (~230GB) exceeds usable memory (~84.5GB). Choose a smaller model or step up the hardware.
Not recommended
Use inside the AI Business OS
Llama 3.1 405B suits these AI Business OS agent archetypes:
A model is only the engine. Inside the AI Business OS it is wrapped with permissions, tools, connectors, RAG and audit so it can actually do business work safely — see how the AI Business OS works →
Frequently asked questions
What hardware do I need to run Llama 3.1 405B?+
At 4-bit you need roughly ~230GB of usable memory. The minimum self-hostable option in our catalog is the Supermicro 8x H100 SuperServer. For a comfortable run we recommend the Supermicro 8x H100 SuperServer.
Which quantization should I use for Llama 3.1 405B?+
Q4_K_M is the usual default — the best size/quality trade-off. Step up to Q8_0 or FP16 if you have spare memory and want higher fidelity.
Should I run Llama 3.1 405B locally or in the cloud?+
Cloud / API is recommended for Llama 3.1 405B. Its size or hosting model makes the cloud the practical choice; pair with smaller local models for everyday private work.
Other sizes in the Llama family
All Llama models →Same family, different size. Pick the variant that fits your hardware.
Related models
Similar picks — family siblings and nearest-size models of the same kind.
Use Llama 3.1 405B inside your AI Business OS
BrainOutput helps you run Llama 3.1 405B as a private business agent — wrapped with the tools, connectors, RAG and guardrails it needs to do real work on hardware you control.
Use this model in your AI Business OS