Mixture-of-Kittens: MoE Megakernel for NVL72s
On the map: Mixture-of-experts → Efficient MoE training and inference systems
Abstract (arXiv)
AI accelerator systems are rapidly consolidating into scale-up architectures, where tens to thousands of GPUs communicate over high-bandwidth, single-hop fabrics. We find that existing Mixture-of-Experts (MoE) training systems, optimized for conventional scale-out networks, transfer poorly to this setting, often running slower than a naive baseline built with PyTorch and NCCL. With industry roadmaps pointing toward even larger scale-up domains, understanding the performance tradeoffs of this hardware regime is increasingly important. We present Mixture-of-Kittens (MoK), an MoE training system designed for Nvidia NVL72. MoK builds on three insights that unlock performance on scale-up domains: (1) choosing push- or pull-based communication per operator, (2) restructuring the computation-communication overlap, and (3) fully eliminating CPU-GPU synchronization. MoK distills these insights into a single deterministic training megakernel that fuses token dispatch, shared and routed expert FFNs, and token combine. Across MoE layer shapes from four widely used open-weight models, MoK delivers up to 2.37× the throughput of the strongest publicly available baseline. In a production run on 512 GPUs spanning multiple GB300 NVL72 racks, MoK improves end-to-end training throughput by 1.41×.
Key facts. No citing papers in the map yet (data through 7 Oct 2026). Placed in Efficient MoE training and inference systems, one of 12 directions in Mixture-of-experts. Builds on 30 of its 50 references that are in the map. First posted on arXiv 28 Sep 2026.
Builds on
30 of 50 references.
Closest ancestors · 9
Same direction, newest first
- 2026Scalable Training of Mixture-of-Experts Models with Megatron Core8 Mar
- 2025SonicMoE: Accelerating MoE with IO and Tile-aware Optimizations16 Dec
- 2025FlashMoE: Fast Distributed MoE in a Single Kernel5 Jun
- 2025Comet: Fine-grained Computation-communication Overlapping for Mixture-of-Experts27 Feb
- 2025FSMoE: A Flexible and Scalable Training System for Sparse Mixture-of-Experts Models18 Jan
- 2024Scattered Mixture-of-Experts Implementation13 Mar
- 2022MegaBlocks: Efficient Sparse Training with Mixture-of-Experts29 Nov
- 2022Tutel: Adaptive Mixture-of-Experts at Scale7 Jun
- 2022DeepSpeed-MoE: Advancing Mixture-of-Experts Inference and Training to Power Next-Generation AI Scale14 Jan
Other references · 21
- 2019PyTorch: An Imperative Style, High-Performance Deep Learning Librarycited by 20,160
- 2020Scaling Laws for Neural Language Modelscited by 6,411
- 2023Efficient Memory Management for Large Language Model Serving with PagedAttentioncited by 5,767
- 2017Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layercited by 3,413
- 2021Switch Transformers: Scaling to Trillion Parameter Models with Simple and Efficient Sparsitycited by 3,014
- 2019Megatron-LM: Training Multi-Billion Parameter Language Models Using Model Parallelismcited by 1,829
- 2020GShard: Scaling Giant Models with Conditional Computation and Automatic Shardingcited by 1,601
- 2023SGLang: Efficient Execution of Structured Language Model Programscited by 1,107
- 2026GLM-5: from Vibe Coding to Agentic Engineeringcited by 502
- 2023Ring Attention with Blockwise Transformers for Near-Infinite Contextcited by 448
- 2018An Empirical Model of Large-Batch Trainingcited by 268
- 2023TPU v4: An Optically Reconfigurable Supercomputer for Machine Learning with Hardware Support for Embeddingscited by 198
9 more
- 2018Measuring the Effects of Data Parallelism on Neural Network Trainingcited by 190
- 2023Microscaling Data Formats for Deep Learningcited by 132
- 2024NanoFlow: Towards Optimal Large Language Model Serving Throughputcited by 85
- 2024FLUX: Fast Software-based Communication Overlap On GPUs Through Kernel Fusioncited by 53
- 2025Triton-distributed: Programming Overlapping Kernels on Distributed AI Systems with the Triton Compilercited by 24
- 2026Composer 2 Technical Reportcited by 20
- 2025MPK: A Compiler and Runtime for Mega-Kernelizing Tensor Programscited by 14
- 2025ParallelKittens: Systematic and Practical Simplification of Multi-GPU AI Kernelscited by 11
- 2026Demystifying NVSHMEM: A System-Level Analysis on Symmetric Memory and Device-Initiated Operations in GPU Communicationcited by 4
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Similar, not cited
Close in wording, no citation either way
- 2025X-MoE: Enabling Scalable Training for Emerging Mixture-of-Experts Architectures on HPC Platforms
- 2025MegaScale-MoE: Large-Scale Communication-Efficient Training of Mixture-of-Experts Models in Production
- 2026Fine-grained Computation-Communication Overlap via Tile-level Signaling and Scheduling for Mixture-of-Experts
- 2026Mixture-of-Parallelisms: Towards Memory-Efficient Training Stack for Mixture-of-Experts Models
- 2022HetuMoE: An Efficient Trillion-scale Mixture-of-Expert Distributed Training System
- 2026Expert Coupling in MoE Pretraining: Reducing All-to-All Overhead with Correlated Placement and Token Shuffling
- 2024Optimizing Mixture-of-Experts Inference Time Combining Model Deployment and Communication Scheduling
- 2025HeterMoE: Efficient Training of Mixture-of-Experts Models on Heterogeneous GPUs