Model comparison
Llama 3.1 405B vs Nemotron Ultra 253B
Head-to-head evidence from 11 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Llama 3.1 405B #102 (Estimated); Nemotron Ultra 253B #150 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Llama 3.1 405B and Nemotron Ultra 253B share 11 comparable benchmark results. 0 of 8 categories are comparable. 0 results are unique to Llama 3.1 405B; 0 to Nemotron Ultra 253B.
Updated July 20, 2026- Shared results
- 11
- Llama 3.1 405B only
- 0
- Nemotron Ultra 253B only
- 0
- Comparable categories
- 0 / 8
Benchmark data for Llama 3.1 405B and Nemotron Ultra 253B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 11 shared benchmark results across 5 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Llama 3.1 405B has the larger context window at 128K, compared with 32K for Nemotron Ultra 253B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Llama 3.1 405B | Nemotron Ultra 253B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Llama 3.1 405B$0 input / $0 output | Nemotron Ultra 253B$0 input / $0 output | Listed prices are equal. |
| Generation speedtokens per second | Llama 3.1 405B29 tok/s | Nemotron Ultra 253BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Llama 3.1 405B2.19 s | Nemotron Ultra 253BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Llama 3.1 405B128K | Nemotron Ultra 253B32K | Llama 3.1 405B lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | Llama 3.1 405B | Nemotron Ultra 253B | Result |
|---|---|---|---|
| τ²-bench resultsSource | 19% | 11.4% | Llama 3.1 405B leads |
Coding1 benchmarks
| Benchmark | Llama 3.1 405B | Nemotron Ultra 253B | Result |
|---|---|---|---|
| AA-SciCodeSource | 29.9% | 34.7% | Nemotron Ultra 253B leads |
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | Llama 3.1 405B | Nemotron Ultra 253B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 8.5% | 9.1% | Nemotron Ultra 253B leads |
| AA-GPQA DiamondSource | 51.5% | 72.8% | Nemotron Ultra 253B leads |
| AA-HLESource | 4.2% | 8.1% | Nemotron Ultra 253B leads |
| AA-Omniscience IndexSource | -17.3% | -45.5% | Llama 3.1 405B leads |
| AA-Omniscience AccuracySource | 22.3% | 19.9% | Llama 3.1 405B leads |
| AA-Omniscience Hallucination RateSource | 51.0% | 81.7% | Llama 3.1 405B leads |
Inst. Following1 benchmarks
| Benchmark | Llama 3.1 405B | Nemotron Ultra 253B | Result |
|---|---|---|---|
| AA-IFBenchSource | 39.0% | 38.2% | Llama 3.1 405B leads |
Frequently Asked Questions (3)
Can I compare Llama 3.1 405B and Nemotron Ultra 253B on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Llama 3.1 405B and Nemotron Ultra 253B today?
Llama 3.1 405B: $0.00 input / $0.00 output per 1M tokens Nemotron Ultra 253B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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