Llama 3.1 405B
Model Overview
Llama 3.1 405B is Meta’s flagship open-weights model, released on July 23, 2024. With 405 billion parameters and a 128K context window, it is the largest openly available foundation model to date. Meta reports that Llama 3.1 405B closes the gap with closed-source flagships like GPT-4o and Claude 3.5 Sonnet on MMLU, HumanEval, and MATH, enabling organizations that require full model control — for regulatory, privacy, or customization reasons — to deploy a near-frontier model on their own infrastructure. The weights are released under the Llama 3 Community License, which permits commercial use for organizations with fewer than 700 million monthly active users. The model is available via major cloud providers (AWS, Azure, Google Cloud) and self-hosted on clusters of 8× H100 GPUs or equivalent.
Key Specifications
| Attribute |
Value |
| Vendor |
Meta |
| Version |
3.1-405b |
| Release Date |
2024-07-23 |
| Context Window |
128,000 tokens |
| Input Modalities |
text |
| Output Modalities |
text |
| License |
Llama 3 Community License |
| Documentation |
https://llama.meta.com/docs/ |
| Benchmark |
Score |
Unit |
Notes |
| MMLU |
88.6 |
% |
5-shot |
| HumanEval |
89.0 |
pass@1 |
— |
| GSM8K |
89.2 |
% |
0-shot CoT |
| MATH |
73.8 |
% |
0-shot CoT |
| BBH |
82.9 |
% |
3-shot CoT |
Pricing
| Tier |
Price (per 1M tokens) |
| Input (Together AI hosted) |
$5.00 |
| Output (Together AI hosted) |
$15.00 |
| Cache Read |
$0.00 |
| Cache Write |
$0.00 |
Pricing source: https://www.together.ai/pricing (as of 2024-08-01). Self-hosted pricing depends on GPU infrastructure cost.
Strengths
- Largest open-weights model available, with near-frontier performance.
- Full model control for regulatory-sensitive industries (defense, healthcare, finance).
- Llama 3 Community License permits commercial use for most organizations.
- Mature ecosystem with vLLM, TGI, and TensorRT-LLM serving stacks.
Weaknesses
- Requires significant GPU infrastructure (8× H100 80GB recommended) to self-host.
- No native multimodal support (text-only).
- Self-hosting introduces operational complexity for inference, scaling, and monitoring.
Use Cases
- On-premise deployments for regulated industries.
- Custom fine-tuning and domain-specific adaptation.
- Sovereign AI initiatives requiring full data control.
- Research workloads needing weight-level access.
References