Verdict
Built from the measurements below
- Accuracy is too close to call: DeepSeek V4.1 Flash 1017 scored 73.8% and DeepSeek V4 Pro 0813 71.2% on the same 80 questions, a gap within what chance alone could produce.
- DeepSeek V4.1 Flash 1017 is 4.0× cheaper per question as billed ($0.00091 vs $0.0036), reasoning tokens included.
- Output speed is similar (57 vs 56 tokens per second).
Which should you choose?
Choose DeepSeek V4.1 Flash 1017 for the lower cost per correct answer ($0.0012 against $0.0051) and more hosts to choose from on OpenRouter (30 against 23).
Accuracy gap +2.5 points (z = 0.35). We call a winner only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.