Verdict
Built from the measurements below
- Accuracy is too close to call: Solar Mini 4 scored 41.2% and Solar Pro 4 45.0% on the same 80 questions, a gap within what chance alone could produce.
- Solar Mini 4 is 3.5× cheaper per question as billed ($0.00053 vs $0.0018), reasoning tokens included.
- Solar Mini 4 generates text 1.2× faster: 107 tokens per second against 91.
- Solar Pro 4 starts answering sooner: 0.6 s to the first token, against 0.7 s for Solar Mini 4.
Which should you choose?
Choose Solar Mini 4 for the lower cost per correct answer ($0.0013 against $0.0041) and faster streaming. Choose Solar Pro 4 for a quicker first token. The widest subject gap is in medicine: Solar Pro 4 answered 5 of 11 correctly, Solar Mini 4 2 of 11. With so few questions per subject, treat this as a lead to test on your own prompts, not a result.
Accuracy gap -3.8 points (z = -0.48). We call a winner only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.