Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning): The Ultimate Performance & Pricing Comparison

Deep dive into reasoning, benchmarks, and latency insights.

The Final Verdict in the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) Showdown

After a comprehensive analysis, Grok 4.1 Fast (Reasoning) emerges as the superior choice for users prioritizing raw intelligence and reasoning. However, Llama 3.1 Instruct 405B remains a highly competitive option, especially for scenarios demanding faster response times and cost-efficiency. This detailed Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) comparison will break down every critical metric to help you make the best decision.

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Model Snapshot

Key decision metrics at a glance.

Llama 3.1 Instruct 405B

Overall Capabilities

The capability radar provides a holistic view of the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) matchup. This chart illustrates each model's strengths and weaknesses at a glance, forming a cornerstone of our Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) analysis.

This radar chart visually maps the core capabilities (reasoning, coding, math proxy, multimodal, long context) of `Llama 3.1 Instruct 405B` vs `Grok 4.1 Fast (Reasoning)`.

Benchmark Breakdown

For a granular look, this chart directly compares scores across standardized benchmarks. In the critical MMLU Pro test, a key part of the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) debate, Llama 3.1 Instruct 405B scores 10 against Grok 4.1 Fast (Reasoning)'s 90. This data-driven approach is essential for any serious Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) comparison.

This grouped bar chart provides a side-by-side comparison for each benchmark metric.

Speed & Latency

Speed is a crucial factor in the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) decision for interactive applications. The metrics below highlight the trade-offs you should weigh before shipping to production.

Time to First Token

Llama 3.1 Instruct 405B300ms

Grok 4.1 Fast (Reasoning)300ms

Tokens per Second

Llama 3.1 Instruct 405B24.823

Grok 4.1 Fast (Reasoning)156.575

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The Economics of Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning)

Power is only one part of the equation. This Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) pricing analysis gives you a true sense of value.

Pricing Breakdown

Compare input and output pricing at a glance.

Real-World Cost Scenario

To process 1M input tokens and generate 250k output tokens, Llama 3.1 Instruct 405B would cost $0.005, whereas Grok 4.1 Fast (Reasoning) would cost $0.000. This practical calculation is vital for any developer considering the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) choice.

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Which Model Wins the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) Battle for You?

Choose Llama 3.1 Instruct 405B if...

Cost is a secondary concern to power in your Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) decision.

You need the most advanced reasoning capabilities available.

Your use case demands cutting-edge AI performance.

Choose Grok 4.1 Fast (Reasoning) if...

You need a highly responsive model for user-facing applications.

Your budget is a primary consideration in the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) choice.

You are developing at scale where operational costs are critical.

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Your Questions about the Llama 3.1 Instruct 405B vs Grok 4.1 Fast (Reasoning) Comparison

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Data source: https://artificialanalysis.ai/