HackerPapers

arXiv:1701.06538cs.LG

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

Noam Shazeer, Azalia Mirhoseini, Krzysztof Maziarz, Andy Davis, Quoc Le, Geoffrey Hinton, Jeff Dean

Abstract

The capacity of a neural network to absorb information is limited by its number of parameters. Conditional computation, where parts of the network are active on a per-example basis, has been proposed in theory as a way of dramatically increasing model capacity without a proportional increase in computation. In practice, however, there are significant algorithmic and performance challenges. In this work, we address these challenges and finally realize the promise of conditional computation, achieving greater than 1000x improvements in model capacity with only minor losses in computational efficiency on modern GPU clusters. We introduce a Sparsely-Gated Mixture-of-Experts layer (MoE), consisting of up to thousands of feed-forward sub-networks. A trainable gating network determines a sparse combination of these experts to use for each example. We apply the MoE to the tasks of language modeling and machine translation, where model capacity is critical for absorbing the vast quantities of knowledge available in the training corpora. We present model architectures in which a MoE with up to 137 billion parameters is applied convolutionally between stacked LSTM layers. On large language modeling and machine translation benchmarks, these models achieve significantly better results than state-of-the-art at lower computational cost.

arXiv comments
Journal reference
DOI
Subjects
cs.LGMachine Learning cs.CLComputation and Language cs.NENeural and Evolutionary Computing stat.MLMachine Learning (Statistics)

On Hacker News

Linked by 14 identifiable commenters in 16 comments across 16 threads, from Jul 2017 to Jul 2026. Found in 8 HN submissions from Jan 2017 to Dec 2025. Open submission discussions.

Comments linking this paper, per year.

Discussed in comments16 threads

  1. Kimi-K3 Technical Report [pdf] 1 comment
    • With slightly different cherry-picking, you could equally well claim that DeepSeek couldn't ship a reasoning model until they copied the idea from OpenAI's o1-preview, and they also copied MoEs from Google Brain/Jagellonian University https://arxiv.org/abs/1701.06538 way back in…

      yorwbaView on HNParent context

    • The paper itself is fairly popular, with several thousand citations. Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layer Noam Shazeer, Azalia Mirhoseini, Krzysztof Maziarz, Andy Davis, Quoc Le, Geoffrey Hinton, Jeff Dean…

      fragmedeView on HNParent context

  2. The Llama 4 herd 1 comment
    • From what I can gather it depends, but could be a simple Softmax-based layer[1] or just argmax[2]. There was also a recent post[3] about a model where they used a cross-attention layer to let the expert selection be more context aware. [1]: https://arxiv.org/abs/1701.06538 [2]…

      magicalhippoView on HNParent context

    • Bit late to the party and I'm not into the AI scene, but from glossing over the three key papers they cite to describe their model, my take is as follows. The idea from LoRA[1] is to take pre-trained, dense weights W_0 for a model and adapt them to new training data by using the…

      magicalhippoView on HNParent context

    • There is an 'old' paper https://arxiv.org/abs/1701.06538 but I believe there needs to be renewed effort in this direction.

      ajtejankarView on HNParent context

  3. Mixtral of experts 1 comment
    • The Sparse Mixture of Experts neural network architecture is actually an absolutely brilliant move here. It scales fantastically, when you consider that (1) GPU RAM is way too expensive, in financial dollars, (2) SSD / CPU RAM are relatively cheap, and (3) you can have "experts"…

      legelView on HNParent context

    • [Relevant paper](https://arxiv.org/abs/1701.06538). TL;DR you can think of it as the initial part of the model is essentially dedicated to learning which experts to choose.

      rishabhjain1198View on HNParent context

    • A huge misconception is that MoE is an ensemble of discrete models, when it is in fact multiple FFNN modules that share an attention and embedding module. Basically the idea is that there's some pars of the model (attention/embedding) that should be trained on everything and…

      RC_ITRView on HNParent context

    • I assume comments like these, "GPT-4: 8 x 220B experts trained with different data/task distributions and 16-iter inference." https://twitter.com/soumithchintala/status/16712671501017210... https://archive.li/rfFlW I'm not sure the most canonical paper on mixture of experts but…

      bodeckerView on HNParent context

    • This is a sparse model. You can't just compare the parameter count against dense models like GPT-3. Otherwise, Google already had a 137B parameter model in 2017: https://arxiv.org/abs/1701.06538

      ma2rtenView on HNParent context

    • Sparsely activated multitask model is a kind of Jeff Dean's hobby horse. It was published in 2017: https://arxiv.org/abs/1701.06538. My assessment is that it is an intriguing but ultimately failed experiment, like Geoffrey Hinton's capsule network.

      sanxiynView on HNParent context

    • It's pretty much what Google is looking into doing Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layer https://arxiv.org/abs/1701.06538

      andreykView on HNParent context

    • I'd say a hybrid of reinforcement learning, meta-learning, neural net structure evolution, and Google's sparsely gated outrageously large neural nets (https://arxiv.org/abs/1701.06538). I have a new long essay on RL and meta-learning that addresses some of this coming out soon…

      andreykView on HNParent context

    • He also mentions sparsely activating only the neurons that matter, which they explore in https://arxiv.org/pdf/1701.06538.pdf Personally I didn't find it very satisfying, I imagine something more fundamental and self referential.

      shpxView on HNParent context

    • Only a few HN submissions each year are so complete that it is nearly impossible to gather comments to start a discussion. Well done! I wonder how close we are to running these "excessive" ensembles in a production environment. Like how we went from using decision trees to…

      daddyoView on HNParent context

Submitted to Hacker News

Connected through shared HN threads, not inferred similarity or a recommendation.