Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | MiMo-V2.5 | Step 3.5 Flash 2603 |
|---|---|---|
| Input ($/M tokens) | $0.14 | $0.1 |
| Output ($/M tokens) | $0.28 | $0.3 |
Verdict. MiMo-V2.5 wins the overall benchmark matchup 2–0 across 2 overlapping categories, but raw benchmark score is only one input to the decision.
Pricing. Both models sit in the budget bracket for output-token pricing. At 0.9× the per-million-token cost, MiMo-V2.5 is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). MiMo-V2.5 makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. MiMo-V2.5 is strongest on Coding Index (56.8), Intelligence Index (38.0). Step 3.5 Flash 2603 leads on Intelligence Index (26.5).
Speed. On throughput, Step 3.5 Flash 2603 generates tokens at 205 tok/s versus 60 tok/s — about 71% faster. On time-to-first-token, Step 3.5 Flash 2603 responds in 1060ms vs 3810ms, which matters most for chat-style UIs.
Provider. Xiaomi and StepFun sell to overlapping but distinct developer audiences: Xiaomi tends to ship frontier reasoning models with premium positioning, while StepFun often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): MiMo-V2.5 costs $8.40 ($101/year); Step 3.5 Flash 2603 costs $7.50 ($90/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): MiMo-V2.5 ≈ $1.26/run, Step 3.5 Flash 2603 ≈ $1.10/run. At agent/realtime scale (200M input / 100M output per million requests): MiMo-V2.5 ≈ $56/run, Step 3.5 Flash 2603 ≈ $50/run. Step 3.5 Flash 2603 becomes more attractive at higher volume — the absolute per-token pricing difference compounds when you ship at scale.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Step 3.5 Flash 2603 is cheaper overall. Its blended price (3:1 input/output ratio) is $0.15/M tokens vs $0.17/M for MiMo-V2.5.
MiMo-V2.5 wins 2 out of 12 benchmarks compared to 0 for Step 3.5 Flash 2603. See the detailed benchmark chart above for per-category results.
Step 3.5 Flash 2603 generates tokens faster at 205 tok/s vs 60 tok/s. However, Step 3.5 Flash 2603 has lower time-to-first-token (1.06s vs 3.81s).
Choose based on your priorities: Step 3.5 Flash 2603 for lower cost, MiMo-V2.5 for stronger benchmark performance, and Step 3.5 Flash 2603 for faster generation. For latency-sensitive apps, check the TTFT comparison above.