Mistral Devstral 2512 vs Mistral Medium 3.5
Empirical evaluation across autonomous coding benchmarks (SWE-bench Verified, LiveCodeBench), token economics, and multi-agent topology in Swarm.
For autonomous agentic coding where multi-file patch pass rate is paramount, Mistral Devstral 2512 holds the verified advantage (+14.2% advantage). Mistral Medium 3.5 is 2.5x cheaper on input tokens ($0.2/M vs $0.5/M). In Swarm multi-agent clusters, Deploy Mistral Devstral 2512 as Primary Planner / Orchestrator, with Mistral Medium 3.5 as high-throughput Coder subagent.
Mistral Devstral 2512
Coder SubagentMistral Medium 3.5
Finder SubagentStandardized Coding & Reasoning Benchmarks
Verified, contamination-free benchmark scores with direct mathematical deltas.
| Benchmark Metric | Mistral Devstral 2512 | Mistral Medium 3.5 | Performance Delta |
|---|---|---|---|
| SWE-bench VerifiedReal-world GitHub issues resolved autonomously | 59.2% | 45% | Mistral Devstral 2512 (+14.2% advantage) |
| LiveCodeBenchPost-training cutoff algorithmic challenges | 54% | 38% | Mistral Devstral 2512 (+16% advantage) |
| LMSYS Coding EloCrowdsourced blind developer preference | 1360 | 1250 | Mistral Devstral 2512 (+110Elo advantage) |
| AIME (Competition Math)Deep multi-step deductive reasoning | 71.5% | — | Mistral Devstral 2512 (Only measured on 71.5) |
Token Economics & Operational Cost Ratio
Pricing per 1M tokens and prompt caching advantages for long-horizon sessions.
Mistral Medium 3.5 is 2.5x cheaper on input tokens ($0.2/M vs $0.5/M).
Output generation costs differ by 1.88x.
Prompt caching significantly reduces long-horizon AST parsing costs during multi-turn Swarm pairing sessions.
Swarm Multi-Agent Topology Synergy
How Swarm orchestrates Mistral Devstral 2512 and Mistral Medium 3.5 in autonomous engineering clusters.
Mistral Devstral 2512
Recommended: Coder Subagent
High-accuracy code synthesis specifically tuned for autonomous test loops and multi-file patches.
Mistral Medium 3.5
Recommended: Finder Subagent
Executes compliance checks and documentation tasks inside EU boundaries.
When to Choose Which Model
Practical developer recommendations based on real-world engineering workloads.
Choose Mistral Devstral 2512 if:
- ✓59.2% on SWE-bench Verified
- ✓Strong compliance with unified diff and git patch conventions
- ✓Reliable tool execution without syntax errors
- ✓Need Coder Subagent specialization inside Swarm.
Choose Mistral Medium 3.5 if:
- ✓Full EU data sovereignty and strict compliance guarantees
- ✓Balanced 90 TPS throughput and affordable pricing
- ✓Clean instruction adherence and documentation extraction
- ✓Need Finder Subagent specialization inside Swarm.
Frequently Asked Comparison Questions
Which model is better for autonomous software engineering: Mistral Devstral 2512 or Mistral Medium 3.5?
For autonomous agentic coding where multi-file patch pass rate is paramount, Mistral Devstral 2512 holds the verified advantage (+14.2% advantage). Mistral Medium 3.5 is 2.5x cheaper on input tokens ($0.2/M vs $0.5/M). In Swarm multi-agent clusters, Deploy Mistral Devstral 2512 as Primary Planner / Orchestrator, with Mistral Medium 3.5 as high-throughput Coder subagent. On SWE-bench Verified, Mistral Devstral 2512 scores 59.2% vs Mistral Medium 3.5 at 45%.
How do Mistral Devstral 2512 and Mistral Medium 3.5 compare on token pricing and operational economics?
Mistral Medium 3.5 is 2.5x cheaper on input tokens ($0.2/M vs $0.5/M). On cached prompts, Mistral Devstral 2512 costs $0.12/M vs Mistral Medium 3.5 at $0.04/M.
How does Swarm configure Mistral Devstral 2512 and Mistral Medium 3.5 in multi-agent workflows?
Deploy Mistral Devstral 2512 as Primary Planner / Orchestrator, with Mistral Medium 3.5 as high-throughput Coder subagent. Swarm isolates code modifications in independent Git worktrees, allowing both models to operate in parallel without colliding working directories or git branch conflicts.