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Motif 2 12.7B technical report

Junghwan Lim, Sungmin Lee, Dongseok Kim, Taehyun Kim, Eunhwan Park, Jeesoo Lee, Jeongdoo Lee, Junhyeok Lee, Wai Ting Cheung, Dahye Choi, Jaeheui Her, Jaeyeon Huh, Hanbin Jung, Changjin Kang, Beomgyu Kim, Minjae Kim, Taewhan Kim, Youngrok Kim, Hyukjin Kweon, Haesol Lee, Kungyu Lee, Dongpin Oh, Yeongjae Park, Bokki Ryu, Dongjoo Weon

arXiv:2511.07464v1cs.CLcs.AI

TL;DR

Research on competitive language-model capability under constrained model sizes and limited computational resources remains relatively sparse. Motif-2-12.7B scales up Motif-2.6B, pre-trains on a larger, more diverse corpus, and introduces Grouped Differential Attention (GDA). Across diverse benchmarks, Motif-2-12.7B-Base outperforms Gemma-3 12B and 27B and comparable-size Qwen models, while approaching Qwen-3 32B.

  • Problem

    Research on competitive language-model capability under constrained model sizes and limited computational resources remains relatively sparse.

    Source: §1 · p. 1
  • Method

    Motif-2-12.7B scales up Motif-2.6B, pre-trains on a larger, more diverse corpus, and introduces Grouped Differential Attention (GDA).

    Source: §1 · p. 2
  • Results

    Across diverse benchmarks, Motif-2-12.7B-Base outperforms Gemma-3 12B and 27B and comparable-size Qwen models, while approaching Qwen-3 32B.

    Source: §3.3 · p. 5
  • Takeaways & Limitations

    Its open availability and transparent training methodology make Motif-2-12.7B a strong baseline for research on scalable attention and efficient reasoning.

    Source: §1 · p. 2

Abstract

from arXiv · show

We introduce Motif-2-12.7B, a new open-weight foundation model that pushes the efficiency frontier of large language models by combining architectural innovation with system-level optimization. Designed for scalable language understanding and robust instruction generalization under constrained compute budgets, Motif-2-12.7B builds upon Motif-2.6B with the integration of Grouped Differential Attention (GDA), which improves representational efficiency by disentangling signal and noise-control attention pathways. The model is pre-trained on 5.5 trillion tokens spanning diverse linguistic, mathematical, scientific, and programming domains using a curriculum-driven data scheduler that gradually changes the data composition ratio. The training system leverages the MuonClip optimizer alongside custom high-performance kernels, including fused PolyNorm activations and the Parallel Muon algorithm, yielding significant throughput and memory efficiency gains in large-scale distributed environments. Post-training employs a three-stage supervised fine-tuning pipeline that successively enhances general instruction adherence, compositional understanding, and linguistic precision. Motif-2-12.7B demonstrates competitive performance across diverse benchmarks, showing that thoughtful architectural scaling and optimized training design can rival the capabilities of much larger models.

1 Introduction

Motif-2-12.7B addresses the challenge of competitive language-model capability under constrained model sizes and compute. It combines architectural changes, broad pre-training, and staged fine-tuning, with competitive results across reasoning and instruction-following tasks.

  • Motif-2-12.7B is an open-weight model designed for instruction following, multi-step reasoning, and general-purpose language understanding.The report frames its work around the sparse research on competitive capabilities under model-size and computational constraints.Source: §1 · pp. 1–2
  • Grouped Differential Attention reorganizes attention to capture multi-granular token interactions while preserving scalability.The report says it improves efficiency without additional computational cost.Source: §1 · p. 2
  • Pre-training used 5.5 trillion tokens and a linear curriculum that gradually increased STEM, mathematics, and programming data.MuonClip and high-performance parallelism kernels were used to improve throughput and stability during long-sequence training.Source: §1 · p. 2
  • Three-stage supervised fine-tuning progressively targets broad conversational competence, compositional reasoning, and linguistic fluency.The stages use diverse instruction data, curated and synthetic reasoning-focused data, then selective data pruning.Source: §1 · p. 2

2 Architecture

Motif-2-12.7B extends Motif-2.6B while preserving its pretrained representations. The architecture integrates grouped differential attention and expands depth while retaining key inherited components.

  • Width-preserving hypercloning scales Motif-2.6B through direct weight replication, preserving its parameter topology and initialization statistics.The expanded model inherits the predecessor’s activations exactly, maintaining functional continuity.Source: §2 · pp. 2–3
  • Grouped Differential Attention uses a 4:1 ratio of signal-preserving to noise-control groups, selected as the best balance in preliminary experiments.The report describes this as its first large-scale application within the Motif architecture.Source: §2 · p. 3
  • LLaMA-Pro depth scaling adds layers while retaining inherited normalization, positional embeddings, residual scaling, PolyNorm, and tokenizer; Table 1 lists detailed hyperparameters.Source: §2 · p. 3, Table 1 · p. 3

3 Pre-training

Motif-2-12.7B-Base uses a 5.5-trillion-token pre-training recipe with progressively adjusted data mixtures and large-batch optimization. Across knowledge, reasoning, coding, and commonsense benchmarks, it outperforms several smaller open-weight models and approaches Qwen-3 32B.

3.1 Pre-training Data

  • The 5.5-trillion-token corpus spans general English, question answering, chat, multilingual, scientific, mathematical, and programming domains.It aggregates open-source and in-house datasets across general web, multilingual, reasoning, science, mathematics, and code sources.Source: §3.1 · pp. 3–4

3.2 Pre-training Stage and Recipe

  • The data mixture shifts from mostly English web corpora toward gradually increased reasoning, mathematical, and code datasets during training.The mixture is dynamically adjusted at each training step to support a transition from language learning to higher-order reasoning.Source: §3.2 · p. 4
  • Effective batch size scales from 16 million to 80 million tokens, using an internally optimized Muon-Clip variant for parallel and distributed training.Source: §3.2 · p. 4
  • The final annealing phase keeps reasoning data below 10% of total tokens while increasing its share to limit overfitting and narrow reasoning distributions.Mathematics receives more weight than code within that subset; the phase covers roughly 1 trillion tokens and increases maximum sequence length from 4,096 to 16,384.Source: §3.2 · p. 4

3.3 Pre-training Evaluation

  • Motif-2-Base surpasses Gemma-3 12B on MMLU and MMLU-Redux, approaches Qwen-3 14B/32B levels, and records the highest MMLU-Pro score.Source: §3.3 · p. 4
  • 94.9 on GSM8K and 73.6 on MATH exceed comparable-scale open-weight baselines; Motif-2-Base leads with 65.9 on HumanEval and 81.5 on MBPP.Source: §3.3 · pp. 4–5
  • On commonsense benchmarks, scores are slightly below larger counterparts but remain competitive without significant degradation.Source: §3.3 · p. 5
  • Across knowledge, reasoning, coding, and commonsense benchmarks, Motif-2-12.7B-Base outperforms Gemma-3 12B and 27B and Qwen models of comparable size (14B), while approaching Qwen-3 32B.The evaluation compares against officially reported Qwen3 and Gemma3 scores and uses greedy decoding for Motif-2-12.7B-Base.Source: §3.3 · pp. 4–5, Table 2 · p. 5

4 Training System Optimization

Training-system optimization combines fused CUDA kernels with Parallel Muon and pipelined communication/computation to improve throughput and memory efficiency. The evaluations report gains in kernel throughput and parallel training performance, alongside a memory benefit from pipelining.

4.1 Infrastructure and Precision

  • Pretraining ran on 400 H100 GPUs for approximately 272K hours using FP8, with gradients kept in BF16 during the backward pass.Source: §4.1 · p. 6

4.2 Kernel Fusion

  • Hand-written fused CUDA kernels outperform naive PyTorch and torch.compile in both passes; torch.compile reaches up to 12.9× speedup over naive.Source: §4.2 · p. 6, Table 3 · p. 6

4.3 Parallel Muon

  • Parallel Muon distributes gradient subsets across ranks, gathers assigned full matrices, computes Newton–Schulz updates concurrently, then scatters sharded updates; pipelining overlaps phases to improve throughput and reduce memory use.Source: §4.3 · pp. 7–8, Figure 1 · p. 7
  • 571 TFLOPS/GPU versus 80 TFLOPS/GPU yields a 7.1× throughput improvement for non-pipelined Parallel Muon over Distributed Muon.Source: §4.3 · p. 9, Table 4 · p. 9
  • FLOPs-based sorting lifts pipelined throughput by over 21% after pipelining first drops throughput approximately 15.8% versus non-pipelined.Source: §4.3 · p. 9
  • The fully optimized pipelined version is only about 2.1% faster than non-pipelined, while non-pipelined peak memory exceeds pipelined versions by over 4.1× and 3×.The memory comparisons are against the pipelined non-sorted and fully optimized configurations, respectively.Source: §4.3 · p. 9

5 Post-training

Motif-2-12.7B-Instruct uses a three-stage supervised fine-tuning pipeline to build general instruction following, reasoning, and domain specialization. Its reported benchmark performance is comparable to or exceeds similarly sized or larger open-weight models despite using a smaller training corpus.

5.1 Supervised Fine-tuning

  • The three SFT stages progress from general instruction learning to synthetic-data reasoning and domain enhancement, then data-pruned targeted refinement.The pipeline explicitly targets multi-step reasoning, code synthesis, and mathematical problem-solving.Source: §5.1 · p. 10

5.1.1 Stage 1: Large-Scale Supervised Fine-tuning

  • Stage 1 uses approximately 28 million balanced-domain samples, packs sequences up to 16,384 tokens, and unfreezes all model parameters.The training setup also specifies FP8 precision, FSDP, and Parallel Muon kernels.Source: §5.1.1 · p. 10

5.1.2 Stage 2: Synthetic and Targeted Fine-tuning

  • Stage 2 combines quality-screened open instruction data with synthetic examples targeting compositional reasoning, algorithmic problem-solving, and multi-step instruction following.This lower-learning-rate, shorter continuation stage is reported to improve reasoning quality while preserving conversational fluency.Source: §5.1.2 · p. 10

5.1.3 Stage 3: Data-Pruned Refinement

  • Stage 3 filters redundant or low-utility Stage 2 data to reinforce diversity and stabilize reasoning and alignment without changing conversational fluency.The filtering criteria emphasize diversity, reasoning coherence, and linguistic fidelity.Source: §5.1.3 · p. 11

5.2 Post-training Evaluation

  • Evaluation covers general knowledge and alignment, mathematics and text reasoning, and agentic and programming tasks, using official Qwen3 and Gemma3 scores as baselines.Instruct evaluations use temperature 0.6 and a maximum sequence length of 32,768 tokens.Source: §5.2 · p. 11
  • Despite training on 5.5T tokens, Motif-2-12.7B-Instruct performs comparably to or better than similarly sized or larger open-weight models across several benchmarks.The report highlights MATH-500, AIME25, and LiveCodeBench, and contrasts its training corpus with Qwen3's 36T tokens and Gemma3's 12–14T.Source: §5.2 · p. 11

6 Conclusion

The conclusion presents Motif-2-12.7B as an efficient, broadly capable model built through targeted architectural changes and systems-aware training, and previews a reasoning-focused variant.

6 Conclusion

  • Motif-2-12.7B combines width-preserving hypercloning, Llama Pro depth scaling, Grouped Differential Attention, curriculum-aware pre-training, and three-stage SFT.The report characterizes the result as efficient and broadly capable without extreme parameter counts.Source: §6 · p. 12
  • Fused PolyNorm kernels and Parallel Muon are reported to provide throughput and memory gains at long context, making large-scale training more accessible.Source: §6 · p. 12
  • The report plans to release Motif-2-12.7B-Reasoning, an RL-enhanced variant focused on mathematics and code while maintaining conversational fluency.Source: §6 · p. 12

7 Appendix

The appendix lists contributor roles and names, noting that authors are alphabetically sorted by last name.

7 Appendix

  • Sungmin Lee and Junghwan Lim are credited with technical and management leadership.Source: §7.1 · p. 17
  • Dongseok Kim, Taehyun Kim, Eunhwan Park, Jeesoo Lee, Jeongdoo Lee, and Junhyeok Lee are listed as core contributors.Source: §7.1 · p. 17
  • The appendix lists 17 additional contributors and states that authors are alphabetically sorted by last name.Source: §7.1 · p. 17
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