The AI arena is free today

Open Superagent

Grok Code Fast 1 vs Nemotron 3 Ultra (550B A55B)

Grok Code Fast 1 significantly outperforms across most benchmarks.

xAI · NVIDIA · Updated for 2026

Which is better?

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while Nemotron 3 Ultra (550B A55B) is better at 0 benchmarks. Grok Code Fast 1 significantly outperforms across most benchmarks.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Grok Code Fast 1

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks

Choose Nemotron 3 Ultra (550B A55B)

  • you want the most recent training data — it shipped Jun 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Grok Code Fast 1
xAI
Nemotron 3 Ultra (550B A55B)
NVIDIA
Benchmark wins
1 of 1
0 of 1
Input price
$0.20 / M
— / M
Output price
$1.50 / M
— / M
Context window
256,000
—
Released
Aug 2025
Jun 2026
License
Proprietary
OpenMDW License v1.1

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while Nemotron 3 Ultra (550B A55B) is better at 0 benchmarks.

Grok Code Fast 1 significantly outperforms across most benchmarks.

Mon Aug 24 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Context Window

Maximum input and output token capacity

Only Grok Code Fast 1 specifies input context (256,000 tokens). Only Grok Code Fast 1 specifies output context (10,000 tokens).

xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
NVIDIA
Nemotron 3 Ultra (550B A55B)
Input- tokens
Output- tokens
Mon Aug 24 2026 • llm-stats.com

License

Usage and distribution terms

Grok Code Fast 1 is licensed under a proprietary license, while Nemotron 3 Ultra (550B A55B) uses OpenMDW License v1.1.

License differences may affect how you can use these models in commercial or open-source projects.

Grok Code Fast 1

Proprietary

Closed source

Nemotron 3 Ultra (550B A55B)

OpenMDW License v1.1

Open weights

Release Timeline

When each model was launched

Grok Code Fast 1 was released on 2025-08-28, while Nemotron 3 Ultra (550B A55B) was released on 2026-06-04.

Nemotron 3 Ultra (550B A55B) is 9 months newer than Grok Code Fast 1.

Grok Code Fast 1

Aug 28, 2025

12 months ago

Nemotron 3 Ultra (550B A55B)

Jun 4, 2026

2 months ago

9mo newer

Knowledge Cutoff

When training data ends

Nemotron 3 Ultra (550B A55B) has a documented knowledge cutoff of 2025-09-30, while Grok Code Fast 1's cutoff date is not specified.

We can confirm Nemotron 3 Ultra (550B A55B)'s training data extends to 2025-09-30, but cannot make a direct comparison without Grok Code Fast 1's cutoff date.

Grok Code Fast 1

—

Nemotron 3 Ultra (550B A55B)

Sep 2025

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok Code Fast 1 and Nemotron 3 Ultra (550B A55B) side-by-side, then vote on the output you prefer.

Grok Code Fast 1
✓ Preferred
Nemotron 3 Ultra (550B A55B)
Open in Playground

FAQ

Common questions about Grok Code Fast 1 vs Nemotron 3 Ultra (550B A55B).

Which is better, Grok Code Fast 1 or Nemotron 3 Ultra (550B A55B)?

Grok Code Fast 1 significantly outperforms across most benchmarks. Grok Code Fast 1 is made by xAI and Nemotron 3 Ultra (550B A55B) is made by NVIDIA. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok Code Fast 1 compare to Nemotron 3 Ultra (550B A55B) in benchmarks?

Grok Code Fast 1 scores SWE-Bench Verified: 70.8%. Nemotron 3 Ultra (550B A55B) scores RULER: 94.7%, IMO-AnswerBench: 92.3%, PinchBench: 90.0%, LiveCodeBench v6: 89.0%, GPQA: 87.0%.

What are the context window sizes for Grok Code Fast 1 and Nemotron 3 Ultra (550B A55B)?

Grok Code Fast 1 supports 256K tokens and Nemotron 3 Ultra (550B A55B) supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok Code Fast 1 and Nemotron 3 Ultra (550B A55B)?

Key differences include licensing (Proprietary vs OpenMDW License v1.1). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok Code Fast 1 and Nemotron 3 Ultra (550B A55B)?

Grok Code Fast 1 is developed by xAI and Nemotron 3 Ultra (550B A55B) is developed by NVIDIA.

Related comparisons