Model comparison
Grok 4.1 Fast vs Yi-1.5-34B
Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 30.2 on the Noometry Index.
Last verified . 17 shared benchmarks.
Summary
- They share 17 benchmarks with published results for both. Grok 4.1 Fast scores higher in 8 categories and Yi-1.5-34B in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 42.3 to 21.5.
- Yi-1.5-34B has downloadable open weights; the other is API-only.
Side by side
| Grok 4.1 Fast | Yi-1.5-34B | |
|---|---|---|
| Provider | xAI | 01.AI |
| Noometry Index | 40.9 | 30.2 |
| Released | 2025-06-27 | 2024-05-13 |
| Weights | Proprietary | Open |
| Context window | 128K | — |
| Max output | 30K | — |
| Input $ / M tokens | $0.20 | — |
| Output $ / M tokens | $0.50 | — |
| Results tracked | 32 | 21 |
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Category by category
Coding Grok 4.1 Fast leads
Grok 4.1 Fast: 33.8 (#236), Yi-1.5-34B: 31.9 (#267)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Coding | 1411 | 1169 |
| LMArena WebDev | 1241 | — |
| BigCodeBench Instruct | — | 33.9% |
| BigCodeBench Complete | — | 43.8% |
| ALE-Bench | 394.93 | — |
Agentic & Tool Use Not comparable
Grok 4.1 Fast: 36.1 (#35), Yi-1.5-34B: —
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| 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: 42.3 (#45), Yi-1.5-34B: 21.5 (#195)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1160 |
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |
Math Grok 4.1 Fast leads
Grok 4.1 Fast: 30.9 (#201), Yi-1.5-34B: 25.3 (#248)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Math | 1408 | 1182 |
| MathArena Final-Answer Competitions | 60.9% | — |
| ProofBench | 4% | — |
| MATH Level 5 | — | 25.5% |
Knowledge Grok 4.1 Fast leads
Grok 4.1 Fast: 32.6 (#203), Yi-1.5-34B: 14.8 (#290)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Expert | 1398 | 1144 |
| GPQA Diamond | — | 32% |
| Vectara Hallucination Rate | 17.8% | — |
Multimodal Not comparable
Grok 4.1 Fast: 36.3 (#71), Yi-1.5-34B: —
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Vision | 1201 | — |
Multilingual Grok 4.1 Fast leads
Grok 4.1 Fast: 51.1 (#110), Yi-1.5-34B: 32.5 (#251)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Non-English | 1391 | 1121 |
| LMArena Chinese | 1441 | 1213 |
| LMArena French | 1416 | 1155 |
| LMArena German | 1404 | 1111 |
| LMArena Japanese | 1347 | 1021 |
| LMArena Korean | 1361 | 1005 |
| LMArena Russian | 1387 | 1091 |
| LMArena Spanish | 1411 | 1120 |
Instruction Following Grok 4.1 Fast leads
Grok 4.1 Fast: 72.8 (#127), Yi-1.5-34B: 59.4 (#252)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Instruction Following | 1376 | 1139 |
Long Context Grok 4.1 Fast leads
Grok 4.1 Fast: 42.4 (#121), Yi-1.5-34B: 34.6 (#243)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Longer Query | 1390 | 1144 |
Writing & Preference Grok 4.1 Fast leads
Grok 4.1 Fast: 57.4 (#126), Yi-1.5-34B: 37.6 (#252)
| Benchmark | Grok 4.1 Fast | Yi-1.5-34B |
|---|---|---|
| LMArena Text | 1408 | 1173 |
| LMArena Creative Writing | 1394 | 1135 |
| LMArena Multi-Turn | 1389 | 1153 |
| EQ-Bench Creative Writing | 1327 | — |
Frequently asked questions
Is Grok 4.1 Fast better than Yi-1.5-34B?
Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 30.2 on the Noometry Index.
Is Grok 4.1 Fast or Yi-1.5-34B better for coding?
Grok 4.1 Fast scores higher on coding benchmarks: 33.8 versus 31.9 in the Noometry coding category.
How many benchmarks do Grok 4.1 Fast and Yi-1.5-34B share?
17 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Yi-1.5-34B has 21.