Llama 3.1 405B VS Command R+

2025-12-20

The landscape of Large Language Models (LLMs) has reached a fever pitch with the release of Llama 3.1 405B, Meta's most ambitious open-source project to date. As a "goliath" in the field, it sets a new gold standard for open-weights performance. However, in the practical world of enterprise AI, it faces stiff competition from models like Cohere's Command R+, which is specifically engineered for business workflows and RAG (Retrieval-Augmented Generation).

To help you make an informed decision for your specific use case, we provide a deep-dive comparison based on the original insights from Benchmarks and specs.

1. Technical Specifications & Architecture

Understanding the "under the hood" metrics is crucial for infrastructure planning and latency expectations.

Specification Llama 3.1 405B Command R+
Parameters 405 Billion 104 Billion
Context Window 128K 128K
Max Output Tokens 2K 4K
Tokens Per Second ~26 - 29.5 ~48
Knowledge Cutoff December 2023 ~December 2023

💡 Key Takeaway: While Llama 3.1 405B has nearly 4x the parameters of Command R+, Command R+ is significantly faster (48 tps) and supports double the output length, making it a strong contender for long-form content generation.

2. Performance Benchmarks

Llama 3.1 405B consistently dominates official industry benchmarks, showcasing its superior "raw intelligence."

MMLU (Undergraduate Knowledge)

88.6% vs 75.7%

Llama leads in general knowledge breadth.

HumanEval (Coding)

89.0% vs 71.0%

Llama 405B is a powerhouse for software development.

MATH (Problem Solving)

73.8 vs 44.0

A massive gap in quantitative reasoning capabilities.

3. Practical Reasoning & Logic Tests

Logical Switch Riddle

The Task: Identify which of three switches controls a bulb on the 3rd floor in one attempt.

Llama 3.1 405B: PASSED

Correctly identified the heat method (turning one switch on, waiting, then switching to another). This demonstrates advanced physical-world reasoning.

Command R+: FAILED

Failed to logically isolate the single-try constraint, leading to an incorrect process that relies on guesswork.

Mathematical Precision (Binomial Theorem)

Task: Evaluate (102)^5 using the binomial theorem.

Llama 3.1 405B flawlessly executed the expansion $(100 + 2)^5$ and calculated the final sum: 11,040,808,032. Command R+ correctly identified the method but suffered from calculation hallucinations, resulting in a significantly wrong final answer.

4. Developer Implementation

You can test these models side-by-side using the OpenAI-compatible SDK. Here is a Python snippet to get started:

import openai

client = openai.OpenAI( api_key='', base_url="https://api.aimlapi.com", )

def compare_models(prompt): models = [ "meta-llama/Meta-Llama-3.1-405B-Instruct-Turbo", "cohere/command-r-plus" ]

for model in models:
    response = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": prompt}]
    )
    print(f"--- Model: {model} ---\n{response.choices[0].message.content}\n")
if name == "main": compare_models("Explain the impact of quantum computing on cryptography.") 

5. Pricing Comparison (per 1k Tokens)

Model Input Price Output Price
Llama 3.1 405B $0.00525 $0.00525
Command R+ $0.0025 $0.01

Note: Llama 405B offers a balanced pricing model, whereas Command R+ is cheaper for input (ideal for long context RAG) but more expensive for output.

Final Verdict

Llama 3.1 405B is the undisputed champion for complex reasoning, high-stakes coding, and zero-shot accuracy. It is best suited for developers building applications that require the highest level of intelligence currently available in the open-weights ecosystem.

Command R+ remains a powerful tool for high-throughput workflows and specific RAG implementations where speed and long output capabilities outweigh the need for "genius-level" mathematical or logical precision.

Frequently Asked Questions (FAQ)

Q1: Is Llama 3.1 405B truly better than GPT-4o?

Benchmarks suggest Llama 3.1 405B is highly competitive with GPT-4o, often exceeding it in specific coding and math tasks, while being an open-weight model that allows for more flexible deployment.

Q2: When should I choose Command R+ over Llama 405B?

Choose Command R+ if your primary concern is inference speed (TPS) or if you need to generate long-form documents exceeding 2,000 tokens in a single response.

Q3: Do both models support multilingual tasks?

Yes, both Llama 3.1 and Command R+ are designed for multilingual support, though Llama 3.1 generally shows higher proficiency in a broader range of languages due to its larger training scale.

Q4: What is the benefit of the 128K context window?

A 128K context window allows both models to process roughly 300 pages of text in a single prompt, which is essential for analyzing large documents or maintaining long-running conversations.