Beats tuned baseline
2026
Residual-only unbiased gradient compression
Compress only the difference between the current client gradient and a persistent control variate, rather than compressing the full gradient. As the control variate tracks the client gradient, the residual shrinks and the same communication budget produces less compression noise than direct gradient quantization.
Paper: Theoretical Foundations of Communication-Efficient, Robust, and Practical Distributed and Federated Optimization
arXiv:2608.06563