Model comparison
Grok 4 Fast vs Llama 3.1 Nemotron Ultra 253b v1
Grok 4 Fast is the stronger model overall, scoring 39.4 to 36.7 on the Noometry Index.
Last verified . 10 shared benchmarks.
NVIDIASummary
- They share 10 benchmarks with published results for both. Grok 4 Fast scores higher in 6 categories and Llama 3.1 Nemotron Ultra 253b v1 in 2 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 39.5.
- Llama 3.1 Nemotron Ultra 253b v1 has downloadable open weights; the other is API-only.
Side by side
| Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 | |
|---|---|---|
| Provider | xAI | NVIDIA |
| Noometry Index | 39.4 | 36.7 |
| Released | 2025-09-19 | — |
| Weights | Proprietary | Open |
| Context window | — | — |
| Max output | — | — |
| Input $ / M tokens | — | — |
| Output $ / M tokens | — | — |
| Results tracked | 30 | 11 |
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Category by category
Coding Llama 3.1 Nemotron Ultra 253b v1 leads
Grok 4 Fast: 32.5 (#271), Llama 3.1 Nemotron Ultra 253b v1: 38.4 (#177)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Coding | 1429 | 1312 |
| LMArena WebDev | 1159 | — |
| WeirdML | 42.9% | — |
Agentic & Tool Use Grok 4 Fast leads
Grok 4 Fast: 29.5 (#86), Llama 3.1 Nemotron Ultra 253b v1: 15.7 (#149)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 10% |
| τ²-bench Banking | 15.7% | — |
| Cybench | 30% | — |
| LMArena Search | 1171 | — |
Reasoning Llama 3.1 Nemotron Ultra 253b v1 leads
Grok 4 Fast: 22.2 (#201), Llama 3.1 Nemotron Ultra 253b v1: 26.3 (#134)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Hard Prompts | 1412 | 1316 |
| ARC-AGI-2 | 5.3% | — |
| Kagi LLM Benchmark | 66.1% | — |
| ARC-AGI-1 | 48.5% | — |
| DTBench | 82.7% | — |
| Epoch Capabilities Index | 144.2 | — |
| ForecastBench | 60.5 | — |
Math Grok 4 Fast leads
Grok 4 Fast: 38.9 (#123), Llama 3.1 Nemotron Ultra 253b v1: 37.5 (#152)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Math | 1419 | 1360 |
Knowledge Not comparable
Grok 4 Fast: 32.0 (#214), Llama 3.1 Nemotron Ultra 253b v1: —
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| Vectara Hallucination Rate | 19.7% | — |
| LMArena Expert | 1411 | — |
Multilingual Grok 4 Fast leads
Grok 4 Fast: 51.3 (#111), Llama 3.1 Nemotron Ultra 253b v1: 43.1 (#187)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Non-English | 1396 | 1282 |
| LMArena Russian | 1389 | 1284 |
| LMArena Chinese | 1457 | — |
| LMArena French | 1431 | — |
| LMArena German | 1383 | — |
| LMArena Japanese | 1352 | — |
| LMArena Korean | 1357 | — |
| LMArena Spanish | 1415 | — |
Instruction Following Grok 4 Fast leads
Grok 4 Fast: 73.2 (#121), Llama 3.1 Nemotron Ultra 253b v1: 69.0 (#178)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Instruction Following | 1387 | 1308 |
Long Context Grok 4 Fast leads
Grok 4 Fast: 63.2 (#3), Llama 3.1 Nemotron Ultra 253b v1: 39.5 (#177)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Longer Query | 1415 | 1299 |
| Fiction.LiveBench | 94.4% | — |
Writing & Preference Grok 4 Fast leads
Grok 4 Fast: 60.0 (#102), Llama 3.1 Nemotron Ultra 253b v1: 52.2 (#175)
| Benchmark | Grok 4 Fast | Llama 3.1 Nemotron Ultra 253b v1 |
|---|---|---|
| LMArena Text | 1407 | 1320 |
| LMArena Creative Writing | 1387 | 1314 |
| LMArena Multi-Turn | 1414 | 1317 |
Frequently asked questions
Is Grok 4 Fast better than Llama 3.1 Nemotron Ultra 253b v1?
Grok 4 Fast is the stronger model overall, scoring 39.4 to 36.7 on the Noometry Index.
Is Grok 4 Fast or Llama 3.1 Nemotron Ultra 253b v1 better for coding?
Llama 3.1 Nemotron Ultra 253b v1 scores higher on coding benchmarks: 38.4 versus 32.5 in the Noometry coding category.
How many benchmarks do Grok 4 Fast and Llama 3.1 Nemotron Ultra 253b v1 share?
10 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Llama 3.1 Nemotron Ultra 253b v1 has 11.