Llama 3.1 405B vs SD 3.5 Large

Compare Llama 3.1 405B and SD 3.5 Large: pricing, performance, context window, latency, and best use cases. Side-by-side comparison on XALEN.

Updated 2026-05-21 · By Abhishek Raj · Our methodology

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Feature Llama 3.1 405B SD 3.5 Large
CategoryOpen SourceImage
Parameters405B8B
Context Window128KN/A
Input Price$0.08/1M tokens$0.004/image/1M tokens
Output Price$0.14/1M tokensN/A/1M tokens
Latency~600ms~3s

Choose Llama 3.1 405B when:

  • ✓ Premium tasks
  • ✓ Research
  • ✓ Fine-tuning base
Key Strengths:

Largest open model, Highest open-source quality

Choose SD 3.5 Large when:

  • ✓ Detailed illustrations
  • ✓ Temple artwork
  • ✓ Marketing imagery
Key Strengths:

High quality, Detailed output, Good composition

Verdict: Llama 3.1 405B vs SD 3.5 Large

For cost efficiency, SD 3.5 Large wins at $0.004/image/1M input tokens. For speed, SD 3.5 Large is faster at ~3s. Llama 3.1 405B excels at Premium tasks while SD 3.5 Large is better for Detailed illustrations. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.

Detailed Analysis

Pricing Comparison

Llama 3.1 405B costs $0.08/1M input tokens and $0.14/1M output tokens. SD 3.5 Large costs $0.004/image input and N/A output. SD 3.5 Large is 20.0x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

Llama 3.1 405B has a 128K context window with ~600ms latency. SD 3.5 Large offers N/A context at ~3s. Llama 3.1 405B has the larger context window.

Best For

Llama 3.1 405B (Open Source) is optimized for: Premium tasks, Research, Fine-tuning base. SD 3.5 Large (Image) works best for: Detailed illustrations, Temple artwork, Marketing imagery.

Try Both on XALEN

Both models are available through XALEN's OpenAI-compatible API. Switch between them by changing the model parameter:

from xalen import XALEN

client = XALEN(api_key="xln_test_YOUR_KEY")

# Use Llama 3.1 405B
response_a = client.chat.completions.create(
    model="llama-3-1-405b",
    messages=[{"role": "user", "content": "Your question here"}]
)

# Use SD 3.5 Large
response_b = client.chat.completions.create(
    model="stable-diffusion-3-5-large",
    messages=[{"role": "user", "content": "Your question here"}]
)

Start Building with XALEN

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Get API Key Try in Playground

Frequently Asked Questions

Which is better, Llama 3.1 405B or SD 3.5 Large?

Llama 3.1 405B (Open Source, 405B) offers Largest open model. SD 3.5 Large (Image, 8B) offers High quality. Choose Llama 3.1 405B for Premium tasks or SD 3.5 Large for Detailed illustrations.

How much does Llama 3.1 405B cost vs SD 3.5 Large?

Llama 3.1 405B: $0.08/1M input, $0.14/1M output. SD 3.5 Large: $0.004/image/1M input, N/A/1M output. Both available on XALEN with batch processing at 50% discount.

Can I use both models on XALEN?

Yes. XALEN provides 200+ models through a single OpenAI-compatible API. Switch between Llama 3.1 405B and SD 3.5 Large by changing the model parameter. No code changes needed.

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Last updated: 2026-05-21. Pricing and specifications may change. Check pricing page for latest rates.