Llama 3.1 405B vs E5 Large v2

Compare Llama 3.1 405B and E5 Large v2: 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 E5 Large v2
CategoryOpen SourceEmbedding
Parameters405B335M
Context Window128K512
Input Price$0.08/1M tokens$0.002/1M tokens
Output Price$0.14/1M tokensN/A/1M tokens
Latency~600ms~20ms

Choose Llama 3.1 405B when:

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

Largest open model, Highest open-source quality

Choose E5 Large v2 when:

  • ✓ Classical text search
  • ✓ RAG pipelines
  • ✓ Knowledge retrieval
Key Strengths:

1024 dimensions, Fast, Multi-lingual

Verdict: Llama 3.1 405B vs E5 Large v2

For cost efficiency, E5 Large v2 wins at $0.002/1M input tokens. For speed, E5 Large v2 is faster at ~20ms. Llama 3.1 405B excels at Premium tasks while E5 Large v2 is better for Classical text search. 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. E5 Large v2 costs $0.002 input and N/A output. E5 Large v2 is 40.0x 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. E5 Large v2 offers 512 context at ~20ms. 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. E5 Large v2 (Embedding) works best for: Classical text search, RAG pipelines, Knowledge retrieval.

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 E5 Large v2
response_b = client.chat.completions.create(
    model="e5-large-v2",
    messages=[{"role": "user", "content": "Your question here"}]
)

Start Building with XALEN

200+ AI models. One API. Pay-as-you-go.

Get API Key Try in Playground

Frequently Asked Questions

Which is better, Llama 3.1 405B or E5 Large v2?

Llama 3.1 405B (Open Source, 405B) offers Largest open model. E5 Large v2 (Embedding, 335M) offers 1024 dimensions. Choose Llama 3.1 405B for Premium tasks or E5 Large v2 for Classical text search.

How much does Llama 3.1 405B cost vs E5 Large v2?

Llama 3.1 405B: $0.08/1M input, $0.14/1M output. E5 Large v2: $0.002/1M 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 E5 Large v2 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.