IQuest Research Reveals MuonH Optimizer's Advantage Comes from Implicit Learning Rate Scheduling
IQuest Research team found that the advantage of the MuonH optimizer stems primarily from its implicit effective learning rate scheduling, not from a better update direction. By dynamically adjusting the learning rate of a non-Hyperball optimizer to match MuonH's angular effective learning rate, they reproduced its training dynamics. The study also shows that aggressive learning rate decay for MuonH can accelerate early convergence but may harm final performance.