Model comparison
Grok 4.1 Fast vs Nemotron 3 Ultra
Nemotron 3 Ultra is the stronger model overall, scoring 42.5 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 3.4× less per token, which makes it the better buy when Nemotron 3 Ultra's lead doesn't matter for your workload.
Last verified . 19 shared benchmarks.
NVIDIASummary
- They share 19 benchmarks with published results for both. Grok 4.1 Fast scores higher in 2 categories and Nemotron 3 Ultra in 7 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Nemotron 3 Ultra leads 52.5 to 33.1.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $0.50 / $2.20 for Nemotron 3 Ultra.
- Nemotron 3 Ultra accepts more context: 262K tokens versus 128K.
- Nemotron 3 Ultra has downloadable open weights; the other is API-only.
Side by side
| Grok 4.1 Fast | Nemotron 3 Ultra | |
|---|---|---|
| Provider | xAI | NVIDIA |
| Noometry Index | 41.4 | 42.5 |
| Released | 2025-06-27 | 2026-06-04 |
| Weights | Proprietary | Open |
| Context window | 128K | 262K |
| Max output | 30K | 128K |
| Input $ / M tokens | $0.20 | $0.50 |
| Output $ / M tokens | $0.50 | $2.20 |
| Results tracked | 32 | 30 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Nemotron 3 Ultra leads
Grok 4.1 Fast: 34.1 (#245), Nemotron 3 Ultra: 38.1 (#182)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Coding | 1411 | 1468 |
| FrontierCode | — | 13.6% |
| LMArena WebDev | 1242 | — |
| SciCode | — | 40.3% |
| WeirdML | — | 43.5% |
| ALE-Bench | 394.93 | — |
Agentic & Tool Use Grok 4.1 Fast leads
Grok 4.1 Fast: 36.3 (#39), Nemotron 3 Ultra: 23.4 (#126)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| APEX-Agents | — | 22.7% |
| Berkeley Function Calling Leaderboard | 69.6% | — |
| τ²-bench Banking | 13.1% | — |
| LMArena Search | 1171 | — |
| Vending-Bench 2 | 1,107 | — |
Reasoning Grok 4.1 Fast leads
Grok 4.1 Fast: 43.4 (#49), Nemotron 3 Ultra: 31.0 (#82)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1452 |
| DTBench | 87.7% | 90.1% |
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| CritPt | — | 3.1% |
| Chess Puzzles | — | 12% |
| Mystery Game Puzzles | — | 20% |
| LMCA | — | 36.9% |
| Epoch Capabilities Index | — | 146.17 |
| ForecastBench | 61 | — |
Math Nemotron 3 Ultra leads
Grok 4.1 Fast: 31.9 (#221), Nemotron 3 Ultra: 35.3 (#187)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| ProofBench | 4% | 2% |
| LMArena Math | 1408 | 1457 |
| MathArena Final-Answer Competitions | 60.9% | — |
| OTIS Mock AIME 2024-2025 | — | 86.7% |
Knowledge Nemotron 3 Ultra leads
Grok 4.1 Fast: 33.1 (#207), Nemotron 3 Ultra: 52.5 (#61)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Expert | 1399 | 1472 |
| GPQA Diamond | — | 85.4% |
| Vectara Hallucination Rate | 17.8% | — |
Multimodal Not comparable
Grok 4.1 Fast: 37.0 (#76), Nemotron 3 Ultra: —
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Vision | 1201 | — |
Multilingual Nemotron 3 Ultra leads
Grok 4.1 Fast: 51.0 (#114), Nemotron 3 Ultra: 53.5 (#64)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Non-English | 1391 | 1427 |
| LMArena Chinese | 1441 | 1497 |
| LMArena French | 1415 | 1472 |
| LMArena German | 1404 | 1471 |
| LMArena Korean | 1361 | 1386 |
| LMArena Russian | 1387 | 1417 |
| LMArena Spanish | 1413 | 1454 |
| LMArena Japanese | 1349 | — |
Instruction Following Nemotron 3 Ultra leads
Grok 4.1 Fast: 72.7 (#133), Nemotron 3 Ultra: 74.7 (#88)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Instruction Following | 1376 | 1418 |
Long Context Nemotron 3 Ultra leads
Grok 4.1 Fast: 42.4 (#126), Nemotron 3 Ultra: 43.9 (#81)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Longer Query | 1390 | 1437 |
Writing & Preference Nemotron 3 Ultra leads
Grok 4.1 Fast: 57.2 (#131), Nemotron 3 Ultra: 66.3 (#36)
| Benchmark | Grok 4.1 Fast | Nemotron 3 Ultra |
|---|---|---|
| LMArena Text | 1408 | 1445 |
| LMArena Creative Writing | 1394 | 1398 |
| EQ-Bench Creative Writing | 1327 | 1692 |
| LMArena Multi-Turn | 1389 | 1411 |
Frequently asked questions
Is Grok 4.1 Fast better than Nemotron 3 Ultra?
Nemotron 3 Ultra is the stronger model overall, scoring 42.5 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 3.4× less per token, which makes it the better buy when Nemotron 3 Ultra's lead doesn't matter for your workload.
Which is cheaper, Grok 4.1 Fast or Nemotron 3 Ultra?
Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Nemotron 3 Ultra lists at $0.50 and $2.20.
Is Grok 4.1 Fast or Nemotron 3 Ultra better for coding?
Nemotron 3 Ultra scores higher on coding benchmarks: 38.1 versus 34.1 in the Noometry coding category.
Which has the bigger context window?
Nemotron 3 Ultra does, with 262K tokens against 128K.
How many benchmarks do Grok 4.1 Fast and Nemotron 3 Ultra share?
19 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Nemotron 3 Ultra has 30.