# Nemotron 3.5 Bolt 74B-A9B vs Spark-X2.6-4B

> Side-by-side benchmark comparison for Nemotron 3.5 Bolt 74B-A9B and Spark-X2.6-4B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/nemotron-3-5-bolt-74b-a9b-vs-spark-x2-6-4b
- Last updated: October 20, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Nemotron 3.5 Bolt 74B-A9B leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Nemotron 3.5 Bolt 74B-A9B has the higher overall point estimate 45.19 to 40.14. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in reasoning, where the averages are 72.9 for Nemotron 3.5 Bolt 74B-A9B and 48.8 for Spark-X2.6-4B.
- The biggest single benchmark swing is τ³-bench results in Agentic, with scores of 17.0% and 34.7%.
- Spark-X2.6-4B is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Spark-X2.6-4B also has the larger context window at 1M.

## Model Snapshot

| Property | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B |
|----------|----------|----------|
| Creator | NVIDIA | SparkLLM |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 1M |
| Overall Score | 45.19 | 40.14 |
| Benchmarks Covered | 8 | 20 |
| Pricing (input/output) | Pricing unavailable / Pricing unavailable | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Nemotron 3.5 Bolt 74B-A9B public-lane score: 34.8 (Estimated · #84/131)
- Spark-X2.6-4B public-lane score: 33 (Estimated · #89/131)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 51.0% | Coming soon | Coming soon |
| τ³-bench results | 17.0% | 34.7% | Spark-X2.6-4B |
| BrowseComp | 66.8% | 53.1% | Nemotron 3.5 Bolt 74B-A9B |
| PinchBench | 87.8% | Coming soon | Coming soon |
| MCP Atlas | 52.2% | 62.4% | Spark-X2.6-4B |
| WebArena | 50.9% | Coming soon | Coming soon |
| BFCL v4 | Coming soon | 71.8% | Coming soon |
| τ²-bench results | Coming soon | 86.9% | Coming soon |
| HLE w/ tools | Coming soon | 36.9% | Coming soon |
| Claw-Eval | Coming soon | 69.9% | Coming soon |

### Coding

- Winner: Not comparable
- Nemotron 3.5 Bolt 74B-A9B public-lane score: Coming soon
- Spark-X2.6-4B public-lane score: 30.6 (Estimated · #95/152)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | Coming soon | 54.3% | Coming soon |
| SWE-bench Verified | Coming soon | 62.8% | Coming soon |
| SWE Multilingual | Coming soon | 64.7% | Coming soon |
| SciCode | Coming soon | 36.8% | Coming soon |

### Reasoning

- Winner: Not comparable
- Nemotron 3.5 Bolt 74B-A9B public-lane score: 72.9 (Unranked · 2 rankable rows)
- Spark-X2.6-4B public-lane score: 48.8 (Unranked · 2 rankable rows)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | Coming soon | 53.3% | Coming soon |

### Knowledge

- Winner: Directional only
- Nemotron 3.5 Bolt 74B-A9B public-lane score: 42 (Supported · #113/187)
- Spark-X2.6-4B public-lane score: 43 (Estimated · #109/187)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 86.4% | 77.1% | Nemotron 3.5 Bolt 74B-A9B |
| HLE w/o tools | 25.3% | 17.9% | Nemotron 3.5 Bolt 74B-A9B |
| GPQA | Coming soon | 69.9% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Nemotron 3.5 Bolt 74B-A9B public-lane score: Coming soon
- Spark-X2.6-4B public-lane score: 78.2 (#62/149)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 93.6% | Coming soon |
| IFBench | Coming soon | 75.8% | Coming soon |

### Mathematics

- Winner: Not comparable
- Nemotron 3.5 Bolt 74B-A9B public-lane score: Coming soon
- Spark-X2.6-4B public-lane score: 76.4 (Unranked · 3 rankable rows)

| Benchmark | Nemotron 3.5 Bolt 74B-A9B | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | Coming soon | 91.2% | Coming soon |
| HMMT Feb 2026 | Coming soon | 81.3% | Coming soon |
| IMOAnswerBench | Coming soon | 75.2% | Coming soon |

## FAQ

### Which is better overall, Nemotron 3.5 Bolt 74B-A9B or Spark-X2.6-4B?

Nemotron 3.5 Bolt 74B-A9B has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Nemotron 3.5 Bolt 74B-A9B and Spark-X2.6-4B?

The widest category gap is in reasoning, where the averages are 72.9 for Nemotron 3.5 Bolt 74B-A9B and 48.8 for Spark-X2.6-4B.

### How many benchmarks does Nemotron 3.5 Bolt 74B-A9B cover on BenchLM?

Nemotron 3.5 Bolt 74B-A9B currently has 8 sourced benchmark scores on BenchLM.

### How many benchmarks does Spark-X2.6-4B cover on BenchLM?

Spark-X2.6-4B currently has 20 sourced benchmark scores on BenchLM.

## Related Comparisons

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- [Spark-X2.6-4B vs Nemotron 3.5 Bolt 74B-A9B BF16](/compare/nemotron-3-5-bolt-74b-a9b-bf16-vs-spark-x2-6-4b)
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- [Spark-X2.6-4B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-spark-x2-6-4b)

## Explore More

- [Nemotron 3.5 Bolt 74B-A9B profile](/models/nemotron-3-5-bolt-74b-a9b)
- [Spark-X2.6-4B profile](/models/spark-x2-6-4b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)