Systems and methods for training neural networks. One embodiment is a system that includes a memory configured to store samples of training data for a Deep Neural Network (DNN), and a distributor. The distributor identifies a plurality of work servers provisioned for training the DNN by processing the samples via a model of the DNN, receives information indicating Graphics Processing Unit (GPU) processing powers at the work servers, determines differences in the GPU processing powers between the work servers based on the information, and allocates the samples among the work servers based on the differences.