Model comparison
LFM2.5-8B-A1B vs Nemotron Ultra 253B
Head-to-head evidence from 12 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
BenchAlign evidence: LFM2.5-8B-A1B estimated; Nemotron Ultra 253B estimated. Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. LFM2.5-8B-A1B and Nemotron Ultra 253B share 12 comparable benchmark results. 0 of 8 categories are comparable. 6 results are unique to LFM2.5-8B-A1B; 0 to Nemotron Ultra 253B.
Updated July 16, 2026- Shared results
- 12
- LFM2.5-8B-A1B only
- 6
- Nemotron Ultra 253B only
- 0
- Comparable categories
- 0 / 8
Benchmark data for LFM2.5-8B-A1B and Nemotron Ultra 253B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 12 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.
LFM2.5-8B-A1B 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.
| Category | LFM2.5-8B-A1B | Δ | Nemotron Ultra 253B |
|---|---|---|---|
| Math | LFM2.5-8B-A1B50.0 | MarginNo overlap | Nemotron Ultra 253BNot measured |
| Inst. Following | LFM2.5-8B-A1B68.8 | MarginNo overlap | Nemotron Ultra 253BNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | LFM2.5-8B-A1B | Nemotron Ultra 253B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | LFM2.5-8B-A1B$0 input / $0 output | Nemotron Ultra 253B$0 input / $0 output | Listed prices are equal. |
| Generation speedtokens per second | LFM2.5-8B-A1BNot available | Nemotron Ultra 253BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | LFM2.5-8B-A1BNot available | Nemotron Ultra 253BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | LFM2.5-8B-A1B128K | Nemotron Ultra 253B32K | LFM2.5-8B-A1B lists the larger context window. |
Benchmark Deep Dive
Agentic2 benchmarks
Coding2 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | LFM2.5-8B-A1B | Nemotron Ultra 253B | Result |
|---|---|---|---|
| AA-GPQA DiamondSource | 51.3% | 72.8% | Nemotron Ultra 253B leads |
| AA-HLESource | 6.9% | 8.1% | Nemotron Ultra 253B leads |
| AA-Omniscience IndexSource | -33.3% | -45.5% | LFM2.5-8B-A1B leads |
| AA-Omniscience AccuracySource | 9.4% | 19.9% | Nemotron Ultra 253B leads |
| AA-Omniscience Hallucination RateSource | 47.0% | 81.7% | LFM2.5-8B-A1B leads |
| Artificial Analysis Intelligence IndexSource | 8.3% | 9.1% | Nemotron Ultra 253B leads |
Math3 benchmarks
Frequently Asked Questions (3)
Can I compare LFM2.5-8B-A1B 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 LFM2.5-8B-A1B and Nemotron Ultra 253B today?
LFM2.5-8B-A1B: $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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