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Zachary Charles

13 accepted papers

2025

Communication-Efficient Language Model Training Scales Reliably and Robustly: Scaling Laws for DiLoCo

NeurIPS 2025spotlight

As we scale to more massive machine learning models, the frequent synchronization demands inherent in data-parallel approaches create significant slowdowns, posing a critical challenge to further scaling. Recent work develops an approach (DiLoCo) that relaxes synchronization demands without compromi…

Cited by 0SourceScholar
2025

Scaling Laws for Differentially Private Language Models

ICML 2025poster

Scaling laws have emerged as important components of large language model (LLM) training as they can predict performance gains through scale, and provide guidance on important hyper-parameter choices that would otherwise be expensive. LLMs also rely on large, high-quality training datasets, like tho…

Cited by 2SourcePDFScholar
2023

Gradient Descent with Linearly Correlated Noise: Theory and Applications to Differential Privacy

NeurIPS 2023poster

We study gradient descent under linearly correlated noise. Our work is motivated by recent practical methods for optimization with differential privacy (DP), such as DP-FTRL, which achieve strong performance in settings where privacy amplification techniques are infeasible (such as in federated lear…

Cited by 19SourcePDFScholar
2023

Towards Federated Foundation Models: Scalable Dataset Pipelines for Group-Structured Learning

NeurIPS 2023poster

We introduce Dataset Grouper, a library to create large-scale group-structured (e.g., federated) datasets, enabling federated learning simulation at the scale of foundation models. This library facilitates the creation of group-structured versions of existing datasets based on user-specified partiti…

2021

Adaptive Federated Optimization

ICLR 2021poster

Federated learning is a distributed machine learning paradigm in which a large number of clients coordinate with a central server to learn a model without sharing their own training data. Standard federated optimization methods such as Federated Averaging (FedAvg) are often difficult to tune and exh…

2021

On Large-Cohort Training for Federated Learning

NeurIPS 2021poster

Federated learning methods typically learn a model by iteratively sampling updates from a population of clients. In this work, we explore how the number of clients sampled at each round (the cohort size) impacts the quality of the learned model and the training dynamics of federated learning algorit…

Cited by 130SourcePDFScholar
2019

A Geometric Perspective on the Transferability of Adversarial Directions

AISTATS 2019poster

State-of-the-art machine learning models frequently misclassify inputs that have been perturbed in an adversarial manner. Adversarial perturbations generated for a given input and a specific classifier often seem to be effective on other inputs and even different classifiers. In other words, adversa…

Cited by 24SourcePDFScholar
2019

DETOX: A Redundancy-based Framework for Faster and More Robust Gradient Aggregation

NeurIPS 2019poster

To improve the resilience of distributed training to worst-case, or Byzantine node failures, several recent methods have replaced gradient averaging with robust aggregation methods. Such techniques can have high computational costs, often quadratic in the number of compute nodes, and only have limi…

2019

Does Data Augmentation Lead to Positive Margin?

ICML 2019oral

Data augmentation (DA) is commonly used during model training, as it significantly improves test error and model robustness. DA artificially expands the training set by applying random noise, rotations, crops, or even adversarial perturbations to the input data. Although DA is widely used, its capac…

Cited by 48SourcePDFScholar
2018

ATOMO: Communication-efficient Learning via Atomic Sparsification

NeurIPS 2018poster

Distributed model training suffers from communication overheads due to frequent gradient updates transmitted between compute nodes. To mitigate these overheads, several studies propose the use of sparsified stochastic gradients. We argue that these are facets of a general sparsification method that…

2018

DRACO: Byzantine-resilient Distributed Training via Redundant Gradients

ICML 2018oral

Distributed model training is vulnerable to byzantine system failures and adversarial compute nodes, i.e., nodes that use malicious updates to corrupt the global model stored at a parameter server (PS). To guarantee some form of robustness, recent work suggests using variants of the geometric median…

2018

Stability and Generalization of Learning Algorithms that Converge to Global Optima

ICML 2018oral

We establish novel generalization bounds for learning algorithms that converge to global minima. We derive black-box stability results that only depend on the convergence of a learning algorithm and the geometry around the minimizers of the empirical risk function. The results are shown for non-conv…

Cited by 198SourcePDFScholar