Model comparison
GPT-5-Codex vs Nemotron 3.5 Lightning
Nemotron 3.5 Lightning is the stronger model overall, scoring 40.0 to 37.9 on the Noometry Index.
Last verified . 0 shared benchmarks.
NVIDIASummary
- The widest gap is in reasoning, where GPT-5-Codex leads 30.9 to 26.8.
- Nemotron 3.5 Lightning is cheaper at $0.05 / $0.20 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- GPT-5-Codex accepts more context: 400K tokens versus 262K.
- Nemotron 3.5 Lightning has downloadable open weights; the other is API-only.
Side by side
| GPT-5-Codex | Nemotron 3.5 Lightning | |
|---|---|---|
| Provider | OpenAI | NVIDIA |
| Noometry Index | 37.9 | 40.0 |
| Released | 2025-09-15 | 2026-08-11 |
| Weights | Proprietary | Open |
| Context window | 400K | 262K |
| Max output | 128K | 262K |
| Input $ / M tokens | $1.25 | $0.05 |
| Output $ / M tokens | $10 | $0.20 |
| Results tracked | 3 | 18 |
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Category by category
Coding GPT-5-Codex leads
GPT-5-Codex: 42.4 (#103), Nemotron 3.5 Lightning: 40.4 (#141)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| WeirdML | 54.5% | — |
| LMArena Coding | — | 1375 |
Agentic & Tool Use Not comparable
GPT-5-Codex: 31.0 (#72), Nemotron 3.5 Lightning: —
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| Terminal-Bench | 44.3% | — |
Reasoning GPT-5-Codex leads
GPT-5-Codex: 30.9 (#83), Nemotron 3.5 Lightning: 26.8 (#127)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| LMArena Hard Prompts | — | 1337 |
Math Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 37.5 (#155)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Math | — | 1359 |
Knowledge Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 37.5 (#154)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Expert | — | 1356 |
Multilingual Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 44.0 (#180)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Non-English | — | 1295 |
| LMArena Chinese | — | 1359 |
| LMArena French | — | 1366 |
| LMArena German | — | 1282 |
| LMArena Japanese | — | 1206 |
| LMArena Korean | — | 1238 |
| LMArena Russian | — | 1253 |
| LMArena Spanish | — | 1345 |
Instruction Following Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 69.6 (#170)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Instruction Following | — | 1318 |
Long Context Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 39.9 (#165)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Longer Query | — | 1314 |
Writing & Preference Not comparable
GPT-5-Codex: —, Nemotron 3.5 Lightning: 48.5 (#201)
| Benchmark | GPT-5-Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Text | — | 1327 |
| LMArena Creative Writing | — | 1254 |
| EQ-Bench Creative Writing | — | 1280 |
| LMArena Multi-Turn | — | 1328 |
Frequently asked questions
Is GPT-5-Codex better than Nemotron 3.5 Lightning?
Nemotron 3.5 Lightning is the stronger model overall, scoring 40.0 to 37.9 on the Noometry Index.
Which is cheaper, GPT-5-Codex or Nemotron 3.5 Lightning?
Nemotron 3.5 Lightning is cheaper. It lists at $0.05 per million input tokens and $0.20 per million output tokens; GPT-5-Codex lists at $1.25 and $10.
Is GPT-5-Codex or Nemotron 3.5 Lightning better for coding?
GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 40.4 in the Noometry coding category.
Which has the bigger context window?
GPT-5-Codex does, with 400K tokens against 262K.
How many benchmarks do GPT-5-Codex and Nemotron 3.5 Lightning share?
0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Nemotron 3.5 Lightning has 18.