XiaomiMiMo/MiMo-V2.6-Flash-MOPD

One-line: MOPD (Multi-teacher On-Policy Distillation) upgrade of MiMo-V2.6-Flash-RL that fixes tool-call repetition in agent harnesses — same 309B/15B-active, 1M-ctx, MIT omnimodal stack.

⚠ large — 309B total params; server-class hardware only (see Efficiency). ⚠ Lab-reported benchmarks below are the MiMo-V2.6 technical-report numbers measured on the RL checkpoint; the MOPD checkpoint’s card publishes no new eval tables, but Xiaomi’s blog (2026-09-27) states the broader benchmark suite “held steady” after MOPD. Released Sep 27, 2026 (weights on HF 04:00Z, API since Sep 25).

Coding benchmarks

BenchmarkScoreSource
HumanEval——
HumanEval+——
MBPP——
LiveCodeBench——
Aider polyglot——
SWE-bench Verified—not published
SWE-bench Multilingual——
DeepSWE v1.1 (agentic SWE stand-in)67.9lab (V2.6 report, RL ckpt — holds steady)
ProgramBench26.0lab (V2.6 report, RL ckpt)
MiMo Code Bench (in-house)61.2lab (V2.6 report, RL ckpt)

Agentic / tool-use benchmarks

BenchmarkScoreSource
BFCL——
τ-Bench——
ToolACE——
GAIA——
Toolathlon-Verified73.6lab (V2.6 report, RL ckpt)
AutomationBench v1.0.652.3lab (V2.6 report, RL ckpt)
Terminal Bench 2.187.6lab (V2.6 report, RL ckpt)
Agents’ Last Exam27.6lab (V2.6 report, RL ckpt)
JobBench61.2lab (V2.6 report, RL ckpt)

Reasoning (context only)

BenchmarkScoreSource
MMLU / MMLU-Pro——
GPQA Diamond——
MATH——
AIME 2026——

Efficiency

  • Active params: 15B (of 309B total; 256 routed experts, 8 active; 48 layers hybrid full+SWA, MTP speculative decoder)
  • Context length: 1M tokens
  • VRAM (fp16 rough): ~618GB fp16 — NOT consumer-runnable; on-disk ~311GB (fp8/bf16 mix), needs multi-GPU + quant.

What makes it notable

The MOPD checkpoint is the agentic-reliability patch for the MiMo-V2.6-Flash family: RL scaling surfaced a tool-call-repetition failure mode (e.g. 1.02% exact within-turn repetition rate under OpenCode on Flash-RL) that standard correctness optimization missed. Xiaomi’s fix fuses mixRL + SFT teachers via on-policy distillation (standard MOPD, teacher-prefix OPD, SFT-prefix OPD) in a lightweight run (~$90k total, ~4% of the MixRL restart cost) that folds a repetition-specialized teacher in without moving the broader benchmark suite. For agent-loop users this targets a real operational failure — repeated identical tool calls burning context and wall time — rather than a headline eval. Same 309B/15B-active cost profile as Flash-RL: server-class only; the 9B Distill sibling remains the local entry point.

See also