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arxiv: 2602.08404 · v2 · pith:JAP4O74Znew · submitted 2026-02-09 · 💻 cs.CL

TEAM: Temporal-Spatial Consistency Guided Expert Activation for MoE Diffusion Language Model Acceleration

Pith reviewed 2026-05-25 06:46 UTC · model grok-4.3

classification 💻 cs.CL
keywords mixture of expertsdiffusion language modelsexpert activationtemporal consistencyspatial consistencyinference accelerationparallel decoding
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The pith

MoE diffusion models run 2.2 times faster with consistent expert routing.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

MoE diffusion language models activate many experts at each denoising step, yet only a small subset of tokens ends up accepted, creating unnecessary overhead. The paper observes that routing decisions stay consistent both across successive denoising levels and across token positions in the sequence. TEAM exploits this by selecting only the experts required for decoded and masked tokens while using speculative exploration on candidates. The outcome is substantially fewer experts activated per step while still accepting more tokens overall. This plug-and-play change delivers up to 2.2 times speedup with almost no drop in output quality.

Core claim

Expert routing decisions in MoE dLLMs exhibit strong temporal consistency across denoising levels and spatial consistency across token positions. Leveraging these properties, TEAM applies three complementary strategies that conservatively activate necessary experts for decoded and masked tokens while performing aggressive speculative exploration, resulting in more accepted tokens with fewer activated experts.

What carries the argument

Temporal-spatial consistency guided expert activation that combines conservative selection for decoded and masked tokens with speculative exploration across candidates.

If this is right

  • Inference overhead drops substantially in latency-sensitive settings.
  • Up to 2.2 times speedup is achieved over vanilla MoE dLLM.
  • Performance stays competitive with mainstream autoregressive models.
  • The method integrates without retraining or architecture changes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same consistency patterns may exist in other parallel decoding schemes and could be tested for efficiency gains.
  • Applying the selection logic to non-MoE diffusion models might expose similar activation redundancies.
  • Measuring consistency at different model scales would test how widely the observation holds.

Load-bearing premise

Expert routing choices remain highly consistent from one denoising step to the next and from one token to its neighbors.

What would settle it

Measure the fraction of shared activated experts between consecutive denoising timesteps and between adjacent token positions in a standard MoE dLLM; if the overlap is low, the claimed speedup should not appear without quality loss.

Figures

Figures reproduced from arXiv: 2602.08404 by Linye Wei, Meng Li, Pingzhi Tang, Zixiang Luo.

Figure 1
Figure 1. Figure 1: Activated experts vs. accepted tokens per forward pass in SDAR 30B-A3B. TEAM decodes more tokens with fewer experts activated in an iteration. ments, it becomes a critical bottleneck in scenarios that are highly sensitive to decoding speed and tail latency, as well as on edge platforms with constrained hardware resources. To address this challenge, we propose TEAM, which is de￾veloped based on our core obs… view at source ↗
Figure 2
Figure 2. Figure 2: Temporal-spatial characteristics of expert activation and decoding with the SDAR 30B-A3B model on a prompt from the GSM8K dataset. Results are shown for layers 0, 24, and 47 (of 47). (a) Number of activated experts across decoding iterations. (b) Distribution of experts activated by decoded and masked tokens at step 6 (of 11). (c) Token acceptance positions at each iteration, together with hidden state sim… view at source ↗
Figure 3
Figure 3. Figure 3: Overview of our proposed TEAM. We apply differentiated expert activation and decoding strategies to tokens within each block. For decoded tokens, redundant computation is reduced through one-step delayed caching. For mask tokens (hot), we adopt aggressive multi-branch speculative exploration to exploit idle compute resources and increase the token acceptance rate. For mask tokens (cold), a double-round rou… view at source ↗
Figure 4
Figure 4. Figure 4: Expert activation with speculative exploration in SDAR for a response from the GSM8K dataset, measured at layer 24 (of 47). as it rapidly increases computational intensity and shifts the decoding bottleneck from memory-bound to compute￾bound, often requiring multi-GPU parallelism to achieve meaningful speedups (Xu et al., 2025). In contrast, for MoE architectures, inference latency is dominated by feedfor￾… view at source ↗
Figure 5
Figure 5. Figure 5: Ablation study on the Activated experts Per decoded Token (APT) and speedup compared to the vanilla model. ance. Finally, Limited Activation for Cold Tokens (LAC) strictly confines expert activation to the subset responsible for newly decoded tokens and hot tokens. This design fur￾ther reduces the number of activated experts per decoded token and yields additional speedup, resulting in the highest overall … view at source ↗
read the original abstract

Diffusion large language models (dLLMs) have recently gained significant attention due to their inherent support for parallel decoding. Building on this paradigm, Mixture-of-Experts (MoE) dLLMs with autoregressive (AR) initialization have further demonstrated strong performance competitive with mainstream AR models. However, we identify a fundamental mismatch between MoE architectures and diffusion-based decoding. Specifically, a large number of experts are activated at each denoising step, while only a small subset of tokens is ultimately accepted, resulting in substantial inference overhead and limiting their deployment in latency-sensitive applications. In this work, we propose TEAM, a plug-and-play framework that accelerates MoE dLLMs by enabling more accepted tokens with fewer activated experts. TEAM is motivated by the observation that expert routing decisions exhibit strong temporal consistency across denoising levels as well as spatial consistency across token positions. Leveraging these properties, TEAM employs three complementary expert activation and decoding strategies, conservatively selecting necessary experts for decoded and masked tokens and simultaneously performing aggressive speculative exploration across multiple candidates. Experimental results demonstrate that TEAM achieves up to 2.2x speedup over vanilla MoE dLLM, with negligible performance degradation. Code is released at https://github.com/PKU-SEC-Lab/TEAM-MoE-dLLM.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript introduces TEAM, a plug-and-play framework for accelerating MoE diffusion language models (dLLMs) by exploiting an observed temporal consistency in expert routing across denoising steps and spatial consistency across token positions. It proposes three complementary expert activation and decoding strategies (conservative selection for decoded/masked tokens plus aggressive speculative exploration) that aim to activate fewer experts while still accepting tokens, reporting up to 2.2× speedup over vanilla MoE dLLM with negligible performance degradation.

Significance. If the consistency properties prove robust and the speedup is reproducible across models and settings, the approach could meaningfully lower inference latency for MoE dLLMs, addressing a practical deployment bottleneck. The plug-and-play design is a strength that would facilitate adoption if the empirical claims are substantiated.

major comments (2)
  1. [§3 (Motivating Observation)] §3 (Motivating Observation): The central premise that expert routing decisions exhibit 'strong temporal consistency across denoising levels as well as spatial consistency across token positions' is stated without any quantitative support (e.g., average Jaccard overlap, expert activation correlation coefficients, or per-step/per-position statistics); this quantification is load-bearing because the three proposed strategies rely on it to avoid missing critical experts during conservative and speculative selection.
  2. [§5 (Experiments)] §5 (Experiments): The headline result of 'up to 2.2× speedup ... with negligible performance degradation' is presented without reported experimental details on models, datasets, hardware, baseline MoE dLLM implementations, exact speedup metric (wall-clock vs. FLOPs), number of runs, or error bars; these omissions prevent verification that the speedup is measured correctly and that degradation remains negligible when the consistency assumption is stressed.
minor comments (1)
  1. [Abstract] The abstract states that code is released but provides no pointer to specific artifacts (e.g., which models or scripts) that would aid immediate reproducibility.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback. We address each major comment below and will revise the manuscript to incorporate the suggested improvements for clarity and reproducibility.

read point-by-point responses
  1. Referee: [§3 (Motivating Observation)] §3 (Motivating Observation): The central premise that expert routing decisions exhibit 'strong temporal consistency across denoising levels as well as spatial consistency across token positions' is stated without any quantitative support (e.g., average Jaccard overlap, expert activation correlation coefficients, or per-step/per-position statistics); this quantification is load-bearing because the three proposed strategies rely on it to avoid missing critical experts during conservative and speculative selection.

    Authors: We agree that quantitative support for the temporal and spatial consistency claims in Section 3 would strengthen the motivating observation. In the revised manuscript, we will add explicit metrics including average Jaccard overlap of expert activations across denoising steps, expert activation correlation coefficients across token positions, and per-step/per-position statistics. These additions will directly substantiate the premise and justify the conservative and speculative selection strategies. revision: yes

  2. Referee: [§5 (Experiments)] §5 (Experiments): The headline result of 'up to 2.2× speedup ... with negligible performance degradation' is presented without reported experimental details on models, datasets, hardware, baseline MoE dLLM implementations, exact speedup metric (wall-clock vs. FLOPs), number of runs, or error bars; these omissions prevent verification that the speedup is measured correctly and that degradation remains negligible when the consistency assumption is stressed.

    Authors: We acknowledge the need for fuller experimental details to support verification. The released code repository provides the underlying implementations, but we will expand Section 5 in the revision to explicitly report the models and datasets used, hardware setup, baseline MoE dLLM details, confirmation that speedup is wall-clock time, number of runs, and error bars. Performance degradation is assessed across standard benchmarks and remains negligible; we will also add discussion of robustness when consistency assumptions are stressed. revision: yes

Circularity Check

0 steps flagged

No circularity: empirical heuristic with no load-bearing derivations

full rationale

The paper presents TEAM as a plug-and-play acceleration framework motivated by an empirical observation of temporal and spatial consistency in MoE expert routing for dLLMs. No equations, uniqueness theorems, fitted parameters renamed as predictions, or self-citation chains appear in the provided text that would reduce any claimed result to its own inputs by construction. The three activation/decoding strategies are described as complementary heuristics leveraging the stated observation, with performance validated experimentally rather than derived, rendering the central claims self-contained without circular reduction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the empirical observation of routing consistency, which functions as an unproven domain assumption. No free parameters or invented entities are mentioned in the abstract.

axioms (1)
  • domain assumption Expert routing decisions exhibit strong temporal consistency across denoising levels as well as spatial consistency across token positions.
    This observation is presented as the direct motivation for the three strategies; it is not derived or proven in the abstract.

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discussion (0)

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Forward citations

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Reference graph

Works this paper leans on

30 extracted references · 30 canonical work pages · cited by 1 Pith paper · 13 internal anchors

  1. [1]

    GPT-4 Technical Report

    Achiam, J., Adler, S., Agarwal, S., Ahmad, L., Akkaya, I., Aleman, F. L., Almeida, D., Altenschmidt, J., Altman, S., Anadkat, S., et al. Gpt-4 technical report.arXiv preprint arXiv:2303.08774,

  2. [2]

    Spiffy: Multiplying diffusion llm accel- eration via lossless speculative decoding.arXiv preprint arXiv:2509.18085,

    Agrawal, S., Garrepalli, R., Goel, R., Lee, M., Lott, C., and Porikli, F. Spiffy: Multiplying diffusion llm accel- eration via lossless speculative decoding.arXiv preprint arXiv:2509.18085,

  3. [3]

    Program Synthesis with Large Language Models

    Austin, J., Odena, A., Nye, M., Bosma, M., Michalewski, H., Dohan, D., Jiang, E., Cai, C., Terry, M., Le, Q., et al. Program synthesis with large language models.arXiv preprint arXiv:2108.07732,

  4. [4]

    LLaDA2.0: Scaling Up Diffusion Language Models to 100B

    URL https://arxiv.org/ abs/2512.15745. Chen, C., Borgeaud, S., Irving, G., Lespiau, J.-B., Sifre, L., and Jumper, J. Accelerating large language model decoding with speculative sampling.arXiv preprint arXiv:2302.01318,

  5. [5]

    Dpad: Efficient diffusion language models with suffix dropout.arXiv preprint arXiv:2508.14148,

    Chen, X., Huang, S., Guo, C., Wei, C., He, Y ., Zhang, J., Li, H., Chen, Y ., et al. Dpad: Efficient diffusion language models with suffix dropout.arXiv preprint arXiv:2508.14148,

  6. [6]

    Sdar: A syn- ergistic diffusion-autoregression paradigm for scalable sequence generation.arXiv preprint arXiv:2510.06303,

    Cheng, S., Bian, Y ., Liu, D., Zhang, L., Yao, Q., Tian, Z., Wang, W., Guo, Q., Chen, K., Qi, B., et al. Sdar: A syn- ergistic diffusion-autoregression paradigm for scalable sequence generation.arXiv preprint arXiv:2510.06303,

  7. [7]

    Training Verifiers to Solve Math Word Problems

    Cobbe, K., Kosaraju, V ., Bavarian, M., Chen, M., Jun, H., Kaiser, L., Plappert, M., Tworek, J., Hilton, J., Nakano, R., et al. Training verifiers to solve math word problems. arXiv preprint arXiv:2110.14168,

  8. [8]

    Gemini 2.5: Pushing the Frontier with Advanced Reasoning, Multimodality, Long Context, and Next Generation Agentic Capabilities

    Comanici, G., Bieber, E., Schaekermann, M., Pasupat, I., Sachdeva, N., Dhillon, I., Blistein, M., Ram, O., Zhang, D., Rosen, E., et al. Gemini 2.5: Pushing the frontier with advanced reasoning, multimodality, long context, and next generation agentic capabilities.arXiv preprint arXiv:2507.06261,

  9. [9]

    Efficient-DLM: From Autoregressive to Diffusion Language Models, and Beyond in Speed

    Fu, Y ., Whalen, L., Ye, Z., Dong, X., Diao, S., Liu, J., Wu, C., Zhang, H., Xie, E., Han, S., et al. Efficient-dlm: From autoregressive to diffusion language models, and beyond in speed.arXiv preprint arXiv:2512.14067,

  10. [10]

    Self speculative decoding for diffusion large language models

    Gao, Y ., Ji, Z., Wang, Y ., Qi, B., Xu, H., and Zhang, L. Self speculative decoding for diffusion large language models. arXiv preprint arXiv:2510.04147,

  11. [11]

    The Llama 3 Herd of Models

    URL https://openreview.net/forum? id=j1tSLYKwg8. Grattafiori, A., Dubey, A., Jauhri, A., Pandey, A., Kadian, A., Al-Dahle, A., Letman, A., Mathur, A., Schelten, A., Vaughan, A., et al. The llama 3 herd of models.arXiv preprint arXiv:2407.21783,

  12. [12]

    Mixtral of Experts

    Jiang, A. Q., Sablayrolles, A., Roux, A., Mensch, A., Savary, B., Bamford, C., Chaplot, D. S., Casas, D. d. l., Hanna, E. B., Bressand, F., et al. Mixtral of experts.arXiv preprint arXiv:2401.04088,

  13. [13]

    d2 cache: Accelerating diffusion-based llms via dual adaptive caching.arXiv preprint arXiv:2509.23094,

    Jiang, Y ., Cai, Y ., Luo, X., Fu, J., Wang, J., Liu, C., and Yang, X. d2 cache: Accelerating diffusion-based llms via dual adaptive caching.arXiv preprint arXiv:2509.23094,

  14. [14]

    Mercury: Ultra-Fast Language Models Based on Diffusion

    9 TEAM: Temporal–Spatial Consistency Guided Expert Activation for MoE Diffusion Language Model Acceleration Khanna, S., Kharbanda, S., Li, S., Varma, H., Wang, E., Birnbaum, S., Luo, Z., Miraoui, Y ., Palrecha, A., Ermon, S., et al. Mercury: Ultra-fast language models based on diffusion.arXiv preprint arXiv:2506.17298,

  15. [15]

    Refusion: A diffu- sion large language model with parallel autoregressive decoding.arXiv preprint arXiv:2512.13586, 2025a

    Li, J.-N., Guan, J., Wu, W., and Li, C. Refusion: A diffu- sion large language model with parallel autoregressive decoding.arXiv preprint arXiv:2512.13586, 2025a. Li, S., Gu, J., Liu, K., Lin, Z., Wei, Z., Grover, A., and Kuen, J. Sparse-lavida: Sparse multimodal discrete diffu- sion language models.arXiv preprint arXiv:2512.14008, 2025b. Lightman, H., Ko...

  16. [16]

    DeepSeek-V3 Technical Report

    Liu, A., Feng, B., Xue, B., Wang, B., Wu, B., Lu, C., Zhao, C., Deng, C., Zhang, C., Ruan, C., et al. Deepseek-v3 technical report.arXiv preprint arXiv:2412.19437,

  17. [17]

    Wedlm: Reconciling diffusion language models with standard causal atten- tion for fast inference.arXiv preprint arXiv:2512.22737,

    Liu, A., He, M., Zeng, S., Zhang, S., Zhang, L., Wu, C., Jia, W., Liu, Y ., Zhou, X., and Zhou, J. Wedlm: Reconciling diffusion language models with standard causal atten- tion for fast inference.arXiv preprint arXiv:2512.22737, 2025a. Liu, Z., Yang, Y ., Zhang, Y ., Chen, J., Zou, C., Wei, Q., Wang, S., and Zhang, L. dllm-cache: Accelerating diffu- sion ...

  18. [18]

    d3llm: Ultra-fast diffusion llm using pseudo- trajectory distillation.arXiv preprint arXiv:2601.07568,

    Qian, Y .-Y ., Su, J., Hu, L., Zhang, P., Deng, Z., Zhao, P., and Zhang, H. d3llm: Ultra-fast diffusion llm using pseudo- trajectory distillation.arXiv preprint arXiv:2601.07568,

  19. [19]

    Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layer

    Shazeer, N., Mirhoseini, A., Maziarz, K., Davis, A., Le, Q., Hinton, G., and Dean, J. Outrageously large neural networks: The sparsely-gated mixture-of-experts layer. arXiv preprint arXiv:1701.06538,

  20. [20]

    Sparse-dllm: Accelerating diffu- sion llms with dynamic cache eviction.arXiv preprint arXiv:2508.02558,

    Song, Y ., Liu, X., Li, R., Liu, Z., Huang, Z., Guo, Q., He, Z., and Qiu, X. Sparse-dllm: Accelerating diffu- sion llms with dynamic cache eviction.arXiv preprint arXiv:2508.02558,

  21. [21]

    Every activa- tion boosted: Scaling general reasoner to 1 trillion open language foundation.arXiv preprint arXiv:2510.22115,

    Team, L., Li, A., Liu, B., Hu, B., Li, B., Zeng, B., Ye, B., Tang, C., Tian, C., Huang, C., et al. Every activa- tion boosted: Scaling general reasoner to 1 trillion open language foundation.arXiv preprint arXiv:2510.22115,

  22. [22]

    From next-token to next-block: A principled adaptation path for diffusion llms.arXiv preprint arXiv:2512.06776,

    Tian, Y ., Liang, Y ., Sun, J., Zhang, S., Yang, G., Shu, Y ., Fang, S., Guo, T., Han, K., Xu, C., et al. From next-token to next-block: A principled adaptation path for diffusion llms.arXiv preprint arXiv:2512.06776,

  23. [23]

    Diffusion llms can do faster-than-ar inference via dis- crete diffusion forcing.arXiv preprint arXiv:2508.09192,

    Wang, X., Xu, C., Jin, Y ., Jin, J., Zhang, H., and Deng, Z. Diffusion llms can do faster-than-ar inference via dis- crete diffusion forcing.arXiv preprint arXiv:2508.09192,

  24. [24]

    Orchestrating dual-boundaries: An arithmetic in- tensity inspired acceleration framework for diffusion lan- guage models.arXiv preprint arXiv:2511.21759,

    Wei, L., Chen, W., Tang, P., Guo, X., Ye, L., Wang, R., and Li, M. Orchestrating dual-boundaries: An arithmetic in- tensity inspired acceleration framework for diffusion lan- guage models.arXiv preprint arXiv:2511.21759,

  25. [25]

    Fast- dllm v2: Efficient block-diffusion llm.arXiv preprint arXiv:2509.26328,

    Wu, C., Zhang, H., Xue, S., Diao, S., Fu, Y ., Liu, Z., Molchanov, P., Luo, P., Han, S., and Xie, E. Fast- dllm v2: Efficient block-diffusion llm.arXiv preprint arXiv:2509.26328,

  26. [26]

    and Zhang, J

    Wu, S. and Zhang, J. Free draft-and-verification: Toward lossless parallel decoding for diffusion large language models.arXiv preprint arXiv:2510.00294,

  27. [27]

    Lopa: Scaling dllm inference via looka- head parallel decoding.arXiv preprint arXiv:2512.16229,

    Xu, C., Jin, Y ., Li, J., Tu, Y ., Long, G., Tu, D., Hou, T., Yan, J., and Deng, Z. Lopa: Scaling dllm inference via looka- head parallel decoding.arXiv preprint arXiv:2512.16229,

  28. [28]

    Qwen3 Technical Report

    Yang, A., Li, A., Yang, B., Zhang, B., Hui, B., Zheng, B., Yu, B., Gao, C., Huang, C., Lv, C., Zheng, C., Liu, D., Zhou, F., Huang, F., Hu, F., Ge, H., Wei, H., Lin, H., Tang, J., Yang, J., Tu, J., Zhang, J., Yang, J., Yang, J., Zhou, J., Zhou, J., Lin, J., Dang, K., Bao, K., Yang, K., Yu, L., Deng, L., Li, M., Xue, M., Li, M., Zhang, P., Wang, P., Zhu, Q...

  29. [29]

    Dream 7B: Diffusion Large Language Models

    10 TEAM: Temporal–Spatial Consistency Guided Expert Activation for MoE Diffusion Language Model Acceleration Ye, J., Xie, Z., Zheng, L., Gao, J., Wu, Z., Jiang, X., Li, Z., and Kong, L. Dream 7b: Diffusion large language models.arXiv preprint arXiv:2508.15487,

  30. [30]

    Llada-moe: A sparse moe diffusion language model.arXiv preprint arXiv:2509.24389,

    Zhu, F., You, Z., Xing, Y ., Huang, Z., Liu, L., Zhuang, Y ., Lu, G., Wang, K., Wang, X., Wei, L., et al. Llada-moe: A sparse moe diffusion language model.arXiv preprint arXiv:2509.24389,