Verdict
Built from the measurements below
- Accuracy is too close to call: Ling 3.1 Flash scored 41.2% and Nemotron 3.5 Lightning 43.8% on the same 80 questions, a gap within what chance alone could produce.
- Nemotron 3.5 Lightning is 1.3× cheaper per question as billed ($0.00049 vs $0.00061), reasoning tokens included.
- Nemotron 3.5 Lightning generates text 16× faster: 116 tokens per second against 7.
- Nemotron 3.5 Lightning starts answering sooner: 0.5 s to the first token, against 1.1 s for Ling 3.1 Flash.
Which should you choose?
Choose Nemotron 3.5 Lightning for the lower cost per correct answer ($0.0011 against $0.0015), faster streaming, a quicker first token, open weights you can run yourself and more hosts to choose from on OpenRouter (4 against 2). The widest subject gap is in engineering: Nemotron 3.5 Lightning answered 4 of 15 correctly, Ling 3.1 Flash 1 of 15. With so few questions per subject, treat this as a lead to test on your own prompts, not a result.
Accuracy gap -2.5 points (z = -0.32). We call a winner only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.