Model Comparison
Llama 3.1 Instruct 405B
vs. GPT-5.3 Codex (xhigh)
Comparing 2 AI models · 12 benchmarks · Meta, OpenAI
Recommended Pick
Op GPT-5.3 Codex (xhigh) 13 metric wins Strongest on: Value, Input price, Throughput
Best Value
GPT-5.3 Codex (xhigh)
100.0 value score
58.6 reasoning / $4.81/1M
Lowest Price
GPT-5.3 Codex (xhigh)
$1.75/1M input price
Best Reasoning
GPT-5.3 Codex (xhigh)
58.6 reasoning score
Blends available reasoning benchmarks
Best for Coding
GPT-5.3 Codex (xhigh)
53.1 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Best value
GPT-5.3 Codex (xhigh) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GPT-5.3 Codex (xhigh) is 1.6x cheaper on input tokens than Llama 3.1 Instruct 405B.
Speed gap
GPT-5.3 Codex (xhigh) generates about 2.4x as many tokens per second as Llama 3.1 Instruct 405B.
Reasoning gap
GPT-5.3 Codex (xhigh) leads Llama 3.1 Instruct 405B by 35.4 points on reasoning.
Coding gap
GPT-5.3 Codex (xhigh) leads Llama 3.1 Instruct 405B by 38.6 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
Llama 3.1 Instruct 405B
Meta
TTFT
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Time
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tok/s
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Tokens
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Cost
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GPT-5.3 Codex (xhigh)
OpenAI
TTFT
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Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
Full Comparison
| Metric | Me Llama 3.1 Instruct 405B | Top Pick Op GPT-5.3 Codex (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $2.75/1M | $1.75/1M |
| Output Cost | $6.50/1M | $14.00/1M |
| Blended (3:1) | $3.69/1M | $4.81/1M |
| Specifications | ||
| Organization | Meta | OpenAI |
| Release Date | Jul 23, 2024 | Feb 5, 2026 |
| Performance & Speed | ||
| Throughput | 36.8 tok/s | 88.2 tok/s |
| TTFT | 652ms | 83405ms |
| Latency | 652ms | 83405ms |
| Composite Indices | ||
| Value Score | 51.5 | 100.0 |
| Reasoning Score | 23.1 | 58.6 |
| Intelligence | 8.5 | 44.3 |
| Coding | 14.5 | 53.1 |
| Math | 3.0 | — |
| Standard Benchmarks | ||
| GPQA | 51.5% | 91.5% |
| MMLU Pro | 73.2% | — |
| HLE | 4.2% | 39.9% |
| LiveCodeBench | 30.5% | — |
| MATH 500 | 70.3% | — |
| AIME 2025 | 3.0% | — |
| AIME (Original) | 21.3% | — |
| SciCode | 29.9% | 53.2% |
| LCR | 24.3% | 74.0% |
| IFBench | 39.0% | 75.4% |
| TAU-bench v2 | 19.0% | 86.0% |
| TerminalBench Hard | 6.8% | 53.0% |
Key Takeaways
GPT-5.3 Codex (xhigh) offers the best value at $1.75/1M, making it ideal for high-volume applications and cost-conscious projects.
GPT-5.3 Codex (xhigh) has the strongest reasoning profile with a 58.6 reasoning score, combining the available reasoning-heavy benchmarks.
GPT-5.3 Codex (xhigh) reaches a 53.1 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
Llama 3.1 Instruct 405B
- General-purpose AI
- Versatile applications
GPT-5.3 Codex (xhigh)
- Cost-sensitive applications
- High-volume processing
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
