Local SGD Optimizes Overparameterized Neural Networks in Polynomial Time
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Abstract (arXiv)
In this paper we prove that Local (S)GD (or FedAvg) can optimize deep neural networks with Rectified Linear Unit (ReLU) activation function in polynomial time. Despite the established convergence theory of Local SGD on optimizing general smooth functions in communication-efficient distributed optimization, its convergence on non-smooth ReLU networks still eludes full theoretical understanding. The key property used in many Local SGD analysis on smooth function is gradient Lipschitzness, so that the gradient on local models will not drift far away from that on averaged model. However, this decent property does not hold in networks with non-smooth ReLU activation function. We show that, even though ReLU network does not admit gradient Lipschitzness property, the difference between gradients on local models and average model will not change too much, under the dynamics of Local SGD. We validate our theoretical results via extensive experiments. This work is the first to show the convergence of Local SGD on non-smooth functions, and will shed lights on the optimization theory of federated training of deep neural networks.
Key facts. Cited by 10 papers in the map (data through 7 Oct 2026). Builds on 34 of its 40 references that are in the map. First posted on arXiv 22 Jul 2021.
Builds on
34 of 40 references.
References · 34
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22 more
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Built on by
Citing papers per year: 2021: 1; 2022: 1; 2023: 4; 2024: 3; 2025: 1.
10 papers.
- 2023FedExP: Speeding Up Federated Averaging via Extrapolationcited by 68
- 2023Provable Multi-Task Representation Learning by Two-Layer ReLU Neural Networkscited by 15
- 2021On the Convergence of Shallow Neural Network Training with Randomly Masked Neuronscited by 11
- 2024The Effectiveness of Local Updates for Decentralized Learning under Data Heterogeneitycited by 7
- 2022Faster Convergence of Local SGD for Over-Parameterized Modelscited by 4
- 2025Widening the Network Mitigates the Impact of Data Heterogeneity on FedAvgcited by 2
- 2024Effectiveness of Distributed Gradient Descent with Local Steps for Overparameterized Modelscited by 1
- 2023On the Convergence of Federated Averaging under Partial Participation for Over-parameterized Neural Networkscited by 0
- 2023Distributed Continual Learning with CoCoA in High-dimensional Linear Regressioncited by 0
- 2024EDiT: A Local-SGD-Based Efficient Distributed Training Method for Large Language Modelscited by 0
- 2025Widening the Network Mitigates the Impact of Data Heterogeneity on FedAvg18 Aug 2025
- 2024Effectiveness of Distributed Gradient Descent with Local Steps for Overparameterized Models10 Dec 2024
- 2024EDiT: A Local-SGD-Based Efficient Distributed Training Method for Large Language Models10 Dec 2024
- 2024The Effectiveness of Local Updates for Decentralized Learning under Data Heterogeneity23 Mar 2024
- 2023Distributed Continual Learning with CoCoA in High-dimensional Linear Regression4 Dec 2023
- 2023On the Convergence of Federated Averaging under Partial Participation for Over-parameterized Neural Networks9 Oct 2023
- 2023Provable Multi-Task Representation Learning by Two-Layer ReLU Neural Networks13 Jul 2023
- 2023FedExP: Speeding Up Federated Averaging via Extrapolation23 Jan 2023
- 2022Faster Convergence of Local SGD for Over-Parameterized Models30 Jan 2022
- 2021On the Convergence of Shallow Neural Network Training with Randomly Masked Neurons5 Dec 2021